20 CHANCES · TAXONOMY CLUES
Animal guessing game
Twenty chances. Can you follow the family-tree clues to the mystery animal? Start with one you know.
Let me guessThink you know animals? Put it to the test.
5 CHANCES PER ROUND · PLAY AGAIN
Animal photo game
Recognize it at first glance? You have five chances, and the photo gets clearer as you go.
Test my eye for detail
5 QUESTIONS PER GAME · PLAY AGAIN
Animal relatives quiz
Does looking alike mean they’re closely related? Five questions to test your instinct.
Test my instinct
3 ROUNDS PER GAME · PLAY AGAIN
Animal order game
You know all four animals. But can you rank them from lightest to heaviest?
Let me rank them
6 × 6 · PURE LOGIC
Animal logic puzzle
The rules are simple. Can you find a place for all six animals using logic alone?
Solve this boardUnlimited rounds. No signup. Progress saved in this browser.
Stay curious a little longer.
ANIMAL DISCOVERY/A fresh trail awaits
Every animal has a story.
Discover one.
One mystery animal.
A whole world of connections.
A whole world of connections.
Twenty chances. Can you follow the family-tree clues to find it?
YOUR EXPEDITION0day streak
Send an animal ahead! Guess a familiar animal. Its shared ancestor with the mystery animal is your first clue.
Next round--:--:--
Swipe sideways to explore the tree. Select a branch to learn more.
| Guess | Shared family | Clue |
|---|
Your guesses will appear here as the trail unfolds.
Your guessesShared ancestry?
The mystery animal
Explore this branch
Along your trail
RECENT GUESSESNo guesses recorded for this round.
A LITTLE NATURAL CURIOSITY
How the trail works.
You don’t need to be a zoologist.
Just bring your curiosity.
Think of an animal.
A familiar favorite is a fine place to start. Search for its name and make your first guess.
Find the connection.
We show the family group your guess shares with the mystery animal. Each branch is a clue.
Follow a new branch.
Use what you’ve learned to get closer. You have 20 chances to make your discovery.
Animal photo game
Recognize it at first glance? You have five chances.
MYSTERY ANIMAL1 / 5
YOUR GUESSES
How to play the animal photo game
-
Look for visual clues
Study the shape, colours, and surroundings. You do not need to know the animal family tree to start.
-
Choose an animal
Search for a name and choose an animal. You have five chances: each guess or skip uses one. Unknown or repeated guesses do not use a chance.
-
Use the full photo, then share
The final three attempts use the full photo. After the round, discover the animal’s name, play again, or share your score without revealing the answer.
Photo game questions
How do I get another photo?
After a round, select Next animal to start a new photo. There is no daily limit. Your current round stays saved when you reload.
Will my progress follow me to another device?
Progress stays in this browser, separately from the family-tree game and relatives quiz. No account is needed, but there is no cross-device sync. Clearing site data removes saved progress.
Does sharing reveal the animal?
The share text includes the date, score, attempt grid, and game link. It does not include the animal name or the photo.
Keep exploring
Prefer choosing between two animals? Try the animal relatives quiz.
Find names and classification in the field guide, or explore surprising connections in our animal stories.
Animal logic puzzle
Simple rules. Can you solve this board on your own?
Tap to place an animal. One per row, column and region; no animals may touch, even diagonally.
Preparing the board…
Animal order game
Know all four animals? Can you rank them by weight?
Preparing three rounds…
Tap two cards to swap, use the arrows, or drag to reorder.
The cards now show the correct order. These are reported adult weight ranges, not exact weights for every individual.
Weight data and sources
Photo credits
How to play animal order
Arrange four animals from lightest to heaviest, then check once per round. Each game has three rounds; after the result, start another game immediately. Answers use sourced adult weight ranges that do not overlap within a round. Progress stays in this browser; shared results do not reveal the animals.
Animal relatives quiz
Look alike, so they’re close relatives? Test your instinct.
Preparing five questions…
Pick one, then discover the connection.
Review your answers
How to play the animal relatives quiz
-
Read the comparison
Each question names one animal and offers two possible relatives. Choose the one that shares the more specific common ancestor.
-
Choose once and discover why
Your choice is locked when you answer. Read the explanation and its NCBI links, then continue when you are ready. There is no timer.
-
Finish five and review
See your score out of five, revisit explanations, then start another game or share a result that keeps the questions and answers secret. Progress stays in this browser.
Relatives quiz questions
Can I play another set?
Yes. After the five-question result, start another set immediately. The reviewed question pool rotates; there is no daily limit.
Can I change an answer or restart a game?
An answer is locked as soon as you choose. Refreshing restores your current game. Finish five comparisons to review the explanations together, then start a new game.
How many questions are available?
The continuous pool contains 500 verified comparisons. Each game rotates through five questions. Questions can reappear when the finite pool cycles.
Keep exploring
Try identifying an animal from its picture in the animal photo game.
Explore the field guide for names and classification, or read the animal stories for more about unexpected relatives.
The field guide
Browse animal profiles ↗No animals found. Try a different name.
Unexpected relatives
Featured reads that make the family tree click.
FIELD NOTE 01A whale’s surprising land connectionBlue whale, hippo, or salmon: water is not a family tree.Read the story ↗FIELD NOTE 02A crocodile’s bird connectionThe mallard beats the wall lizard in this three-way comparison.Read the story ↗FIELD NOTE 03Are Hyenas More Closely Related to Cats or Dogs?Follow the spotted hyena’s family tree: cat-like does not mean a member of the cat family.Read the story ↗
Meet the animals. Follow the questions.
Real sources, surprising adaptations, and a little room to play.
AxolotlAdult life, with the feathery gills still attached.Ambystoma mexicanum ↗
Blue whaleA giant with a very small menu.Balaenoptera musculus ↗
Emperor penguinThe egg has no nest. Dad brings the warm floor.Aptenodytes forsteri ↗
Giant Pacific octopusEight arms. A hidden beak. A very different way to be a mollusc.Enteroctopus dofleini ↗
Giant pandaThe bamboo grip starts in the wrist.Ailuropoda melanoleuca ↗
LionMeet the cat that makes family life a team sport.Panthera leo ↗
Nile hippopotamusThe “river horse” has a surprising family tree.Hippopotamus amphibius ↗
PlatypusEyes shut. Dinner detector on.Ornithorhynchus anatinus ↗
Saltwater crocodileIts name says saltwater. Its range says more.Crocodylus porosus ↗
Western honey beeA flower patch can become a set of dance directions.Apis mellifera ↗
Small stories.
Unexpected connections.
Whales and hippos. Hyenas and cats. Discover unexpected relatives through short reads, clear explanations, and sources you can follow.
FIELD NOTE 01A whale’s surprising land connectionBlue whale, hippo, or salmon: water is not a family tree.Read the story ↗FIELD NOTE 02A crocodile’s bird connectionThe mallard beats the wall lizard in this three-way comparison.Read the story ↗FIELD NOTE 03Are Hyenas More Closely Related to Cats or Dogs?Follow the spotted hyena’s family tree: cat-like does not mean a member of the cat family.Read the story ↗FIELD NOTE 04An octopus’s snail connectionA shared sea is less informative than a shared mollusc branch.Read the story ↗FIELD NOTE 05Are Manatees Related to Hippos or Elephants?Compare a West Indian manatee, African bush elephant and Nile hippopotamus using their shared branches.Read the story ↗FIELD NOTE 06Are Bats More Closely Related to Cats or Mice?Compare the Egyptian fruit bat, domestic cat and house mouse on an animal family tree.Read the story ↗
Unexpected relatives
FOLLOW YOUR CURIOSITY
The animal files
Find an animal, discover an adaptation, then play a little. Each profile links to its evidence.
No profiles match. Try another common or scientific name.
THE ANIMAL FILES
Dog heartworm
Dirofilaria immitis
One life cycle needs two very different hosts.
Dog heartworm is a threadlike parasitic roundworm whose development links mosquitoes with mammal hosts.[1]
Follow the evidence ↓
- A mosquito stage
- Larvae develop inside a mosquito[1]
- A changing location
- Adults occupy pulmonary vessels[1]
- A return route
- Microfilariae circulate in blood[1]
A mosquito stage
A mosquito is more than a vehicle carrying this worm from place to place. Larval development occurs within it before an infective stage can pass onward. The lifecycle therefore depends on the right sequence of hosts, not simply on an adult worm moving directly between neighbouring dogs.[1]
A changing location
The common name emphasizes the heart, but adult worms also occur in the pulmonary arterial system. Development includes migration through tissues before adults reach these vessels.[1]
A return route
Mature females produce young called microfilariae that can circulate in the host’s blood. A feeding mosquito can take up these stages, connecting one part of the cycle to the next. Temperature affects development inside the mosquito.[1]
A COMMON MIX-UP
Does the name mean adults occur only inside the heart?
No. Adults can reside in the pulmonary arterial system as well as the heart.[1]
TRY A LITTLE REASONING
Why is the mosquito an intermediate host rather than merely transport?
Reveal the explanation
The larvae develop within the mosquito. Calling it transport alone would omit a necessary developmental stage in the described lifecycle.[1]
Sources & editorial notes
Adapted and translated from the cited Wikipedia revisions, with source-linked reasoning. Image credit and licence are listed separately above.
Adapted and translated from Wikipedia contributors; exact revisions are linked below. CC BY-SA 4.0
Last fact check:
One discovery leads to another
A LITTLE NATURAL CURIOSITY
How to play AnimalLoop.
Choose a game: follow family-tree clues, identify an animal photo, compare relatives, sort by weight, or solve a logic grid. Every game supports unlimited rounds.
How do I start the family-tree game?
Open the animal guessing game. Search a local common name or scientific name, then choose an animal. On a phone, tap a suggestion to guess immediately; on desktop, select an animal and submit. Every accepted guess uses one of your 20 chances. A wrong guess reveals a shared ancestral branch; use that clue to choose your next animal.
How to play the animal photo game
Identify an animal in five attempts. Start with a clearer pixelated photo; the final three attempts show the full photo. Finish a round and play again immediately.
Search for a name and choose an animal. You have five chances: each guess or skip uses one. Unknown or repeated guesses do not use a chance.
Test my eye for detailHow to play the animal relatives quiz
Compare two animals and choose which is more closely related to the animal in the question. Each game contains five comparisons, with explanations and NCBI sources. Finish one game and start the next.
Your choice is locked when you answer. Read the explanation and its NCBI links, then continue when you are ready. There is no timer.
Test my instinctHow to play animal order
Arrange four animals from lightest to heaviest, then check once per round. Each game has three rounds; after the result, start another game immediately. Answers use sourced adult weight ranges that do not overlap within a round. Progress stays in this browser; shared results do not reveal the animals.
Let me rank themHow to play animal logic
Tap to place an animal. One per row, column and region; no animals may touch, even diagonally.
Use Exclude to mark a square with ×. Tap again to clear it. Undo takes back one action, and a reset can be undone too. Every board has one solution reachable by deduction. Finish a board to start the next; rounds are unlimited and progress stays in this browser.
Solve this boardWhat does a hint cost?
After your first guess, an available branch hint costs three chances. It reveals the next ancestral branch, without naming the answer or revealing a species or a narrower group. When only three chances remain, taking a hint uses them all and ends the round. You can also choose to reveal the answer and finish the round.
What does the family tree show?
The tree follows NCBI Taxonomy, including groups without a formal rank. Branches show classification, not a similarity percentage or a measured time since divergence. Wikipedia may use a different classification.
You must guess the exact catalogued animal. Guessing one of its descendants does not count as a correct answer. When the closest shared branch would name the mystery animal, the game shows a higher ancestor to keep the answer hidden.
Can I keep playing after a game?
Every game supports unlimited rounds. Finish a round, then select the next-game button. Animal guessing lets you continue guessing animals. Historical daily statistics remain saved.
Do I need an account?
No login is needed. Progress, preferences, and statistics are saved with localStorage in this browser. They do not sync between devices or browsers, and clearing site data removes them. See the privacy and source notes.
Where can I learn about the animals?
Browse the field guide for animal names, classification, reading, and source links. Wikipedia excerpts and adaptations identify their source revision and CC BY-SA licence. Image credits link to the creator, original source, and individual licence; check those terms before reusing an image.
NOTES ON THIS EDITION
Privacy & sources.
These notes explain game storage, external links, and the sources behind AnimalLoop.
What stays in your browser
Game progress, preferences, and daily statistics stay in this browser’s localStorage; saved-game storage is not sent to PostHog and does not sync between devices. Clearing site data removes these records. We use PostHog with an anonymous browser identifier to collect key interaction events and sampled session replays, with input contents masked. PostHog may store that identifier in your browser and receive basic device and request information. We respect browser Do Not Track preferences when provided.
Images and external links
Some images load from Wikimedia Commons. Its servers receive normal request information, including your IP address and browser request headers. Following a source link opens an external website, which follows its own privacy policy. See the Wikimedia privacy policy for its practices.
The animal family tree
Classification follows NCBI Taxonomy. The game uses the catalogued lineage, including unranked groups, to connect guesses. It does not measure visual resemblance or genetic similarity, and other sources may use different classifications.
Reading, images, and licences
Wikipedia excerpts and adaptations retain a link to their source revision and credit Wikipedia contributors under Creative Commons Attribution-ShareAlike 4.0. Images have individual licences and creator credits in their field notes; not every image uses the same licence. The local image credits and profile image credits list bundled media sources.
Read the game instructions, explore the field guide, or start an animal guessing game.