Name the bird, spot the lizard, and ID the bear correctly, and win bragging rights in the wild world of animal identification challenges on Twitter. Fail, and find out why from the experts. It’s a fun way to learn about the natural world from behind a computer, and we rounded up a few of our favorites so you can play along, too.

#TrickyBirdID

Tricky Bird ID is a bird identification challenge run by Jason Ward (@JasonWardNY), the community relations and outreach coordinator for the National Audubon Society and host of the web series Birds of North America. He started Tricky Bird ID to break down the basics of bird identification. On an ideal week, he posts a photo of a bird on Monday, Tuesday, and Wednesday at 8PM ET. He tries to use photos where the birds are hiding, or in motion, to make the experience more lifelike, Ward says. “Birds don’t often pose on a nice, well-lit, beautiful branch out in the open,” he says.

People can tweet their guesses for the next 30 minutes before he starts retweeting some of the winning responses. When he tweets the big reveal, he often explains the identification in more depth to help people identify backyard and neighborhood birds on their own. “My overall mission with all of this bird-centric madness is to try and introduce nature and wildlife to underserved, underrepresented communities — kids who look like I do,” says Ward, who’s African American. “We’re trying to create and inspire the next generation of birders of color, who are going to be more numerous than we are.”

#StreetCreatures

This quiz is more like a scavenger hunt. On Fridays around 9AM PT, Seattle-based naturalist and writer Kelly Brenner (@MetroFieldGuide) posts clues to a creature’s ID and also sometimes gifs of Tom Hiddleston as Loki. (This is an observation, not a complaint.) Brenner’s quizzes tend to center around plants or animals that are under-appreciated and under-noticed. “My only rule is it has to be found in a city,” Brenner says.

People research the clues, and direct message Brenner when they think they’ve solved the puzzle. Around 2PM PT, she reveals the answer. “Once the time is up, I talk about each clue, and I like to link to an article or a scientific paper,” she says. While Brenner keeps track of the regular competitors on a leader board, even people who guess wrong get something out of it. “A lot of people who play, they go down the wrong path, so they’ll learn something else about it that was completely unrelated.”

#FindThatLizard

Earyn McGee (@Afro_Herper) is a PhD student at the University of Arizona studying lizards in arid environments, and whether drought and climate change could screw up their food sources. She also studies how to harness social media to bring more African American women into careers in land and water management.

Those two interests come together in #FindThatLizard, a two-day challenge that starts on Tuesdays at 12PM MT when McGee posts a photo of a lizard with a different hashtag: #GuessThatLizard. Based on a snapshot and a few details, people have to guess the name of the lizard in the photo. That’s the lizard that people will have to spot hiding in the next day’s challenge: #FindThatLizard.

The fun starts at 5PM MT on Wednesdays with #FindThatLizard when McGee posts a picture of what — at first glance — is a lizard-less nature scene. But thanks to the previous day’s hints, her followers know where to look. People who think they’ve spotted the lizard (or lizards) respond with a third hashtag, #FoundThatLizard. That’s also the hashtag McGee uses when she posts the answer later that night. The winner, she says, gets bragging rights. But McGee gets something out of it, too. “I have people who tell me that they put it up in their classrooms for their students, and they play the game with their family,” she says. “It’s really heartwarming to me that this thing that I really enjoy doing out in real life is something I can bring to people who might not have had that opportunity otherwise.”

#CougarOrNot

Inspired by other animal ID hashtags, ecologist Michelle LaRue started Cougar or Not back in 2015. She was working with a research nonprofit called The Cougar Network, which had a big database of photos of possible cougar sightings. “I thought it would be a fun game, hopefully educational, and it would give me a chance to do science communication about cougars, predators, and what Cougar Network does,” LaRue says in a direct message on Twitter.

The challenge starts at 11:30AM CT most Fridays, and LaRue keeps tweeting the same photo for two hours before she reveals whether the photo was in fact a cougar, or not. There isn’t really a winner to the game — unless you count the graduate student who’s analyzing the responses to more than 100 photos for her master’s degree.

#CrowOrNo

Kaeli Swift (@corvidresearch), a postdoctoral scientist at Denali National Park, knows that it can be hard for the general public to identify birds in the corvid family, like crows and ravens. She’d seen LaRue’s Cougar or Not game, and one day, it just clicked: “I was like, ‘Oh my gosh, ‘crow or no.’ It rhymes! Of course this has to be a game,” she says. “It was a combination of this need that I saw and my love of rhymes and puns.”

Now, every Wednesday, Swift posts a photo at 11:30AM, and her followers have to guess if it’s a crow, or no. “A crow is any bird with the word crow in its recognized English common name,” Swift says. That could include American crows or Mariana crows, for example. There are a lot of options. So part of the payoff for the challenge is learning the basic birding skill of recognizing these birds. “But it also became a way to teach people about the global biodiversity of this family and this genus of birds,” Swift says.

#KnockKnockWhosBear

Danielle Rivet (@grizzlygirl87), a PhD candidate at the University of Saskatchewan, posts an ambiguous bear photo on Twitter on Tuesdays around noon CT with the hashtag #KnockKnockWhosBear. Her followers respond with guesses about the bear’s species and reasons for the guess, and after an hour she gives them a hint by tweeting the bear’s location. Three hours later, she posts the ID along with the characteristics she used to identify the species.

The challenge started because Rivet spends a lot of time looking at bear photos from her work with a camera trap database at Wapusk National Park in Canada. The camera trap is set up to monitor polar bears, but black bears and brown bears wander into frame, too. And they can be tough to tell apart. “Even for someone who has worked with bears for a long time, it can be challenging to determine what species you’re looking at,” Rivet tells The Verge in an email.

So, she decided to bring the challenge to her followers on Twitter to help them learn how to ID bears. It’s not just an academic exercise, Rivet says: for people who work or travel through bear country, there’s a practical purpose, too. “It’s important to know which species are around, how to identify them, and how to handle an encounter with that animal,” she says. “Plus, bear photos are really fun to look at!”