[♪ INTRO] We all get a bit of joy when animals take  time out of their day to have a little fun.

Seeing puppies tumble over one  another, birds roll around in the snow… it just makes your heart melt. And I have great news for you.

You can add another adorable example  to the list of animals that play. According to a study made available  online last month in the journal Animal Behavior, bumble bees know  how to have a good time, too! Defining an animal behavior  as “play” can be tricky, because it’s not like they’re going  to tell us that they’re playing.

So researchers have sort  of settled on five criteria a behavior needs to meet to be considered play. For example, the animal can’t be  doing it to achieve an obvious goal, like obtaining food, and they have to  be observed doing it more than once. So in a study published back in 2017,  one research lab based in the UK trained a group of bumble bees to  move a ball to a specific location, in exchange for a sugary treat.

While that was not an example of bees  playing, the researchers did notice that their bees would sometimes roll  the balls around for no reward. And if they weren’t doing that for any  obvious reason, maybe the reason was play. So the lab set up a new series  of experiments for what might be the cutest study we’ve ever heard of.

Now, the bees could choose to roll the  balls around only if they wanted to. But why might they want to  roll a bunch of balls around? Bumble bees need to be both  mentally and physically sharp in order to get at the nectar and  pollen in all those flowers they visit.

But bees aren’t born experts. It takes practice for them to hone  their flower-handling abilities. So they might not roll a bunch of balls  around because it makes them happy, but to improve their motor  and problem-solving skills.

Either way, scientists would  consider that a form of play. In their first experiment, 45  bumble bees took their turn inside a box with food on one end, and  a bunch of balls along the walls. This was to test whether the  bees would go out of their way to stop and play with the balls, or  just make a beeline for the food.

And every single bee did roll at least  one ball before making it to their snack. One bee did it 44 times in a single day. Was that the greatest day  in that bee’s life or what?

They also noticed an age-related  trend in the bees’ behavior. Younger bees were more likely to  roll the balls than older bees. That mimics what scientists have  observed in many other species.

Juveniles tend to engage in play more  often than their adult counterparts. In another experiment, the bees had to  pass through both yellow and blue colored chambers, which either did or did not  have balls, in order to reach their food. Eventually, the bees would learn to associate a certain colored chamber as the “ball room”.

So for half of the bees, the  yellow chamber had balls, and the blue one didn’t, and  for the other half it flipped. After training was complete, the setup changed: the bees were presented with a choice. They could choose to enter  the yellow or blue chamber, but not see if either had balls in it.

And generally speaking, the  bees preferred to go into whichever chamber they had  learned was the “ball room”. That suggests that they were actively  looking for some balls to play with. Now while the researchers couldn’t  reveal whether bumble bees play with balls for pure enjoyment, or because  they want to practice some life skills, this study does provide the first  evidence that not just bees, but insects more generally,  will play with objects.

And hey, whether or not bumble bees  play because they want to have fun, humans can definitely have fun watching  the adorable videos of them doing it. Speaking of animals that play, our next  story is about a particular kind of corvid, the family of birds that includes  crows, jays and a bunch of others. Past research has shown that  corvids love to have a good time.

But a study published this week, in the  journal Philosophical Transactions of the Royal Society B, has revealed that corvids  can also have incredible self-control. Corvids like to stash their  food away for another day. This means they have some ability to resist gobbling up the food that they’ve just collected.

And like a kid hiding their  Halloween candy from a snacky parent, corvids must also wait until no  one is looking to stash their food, so that other birds can’t raid their hiding spot. So researchers believe that corvids  have evolved some level of self-control. And one team wanted to  understand how that self-control is linked to the birds’ intelligence.

So to test it, they gave 10 Eurasian  jays a version of the marshmallow test. Generally speaking, this test  has a human child choose between receiving one marshmallow now, or two  if they are able to wait for a bit. And then they have to wait that bit out, with the one marshmallow there in  front of them silently tempting them.

But marshmallows, it turns out, aren’t  really a corvid’s idea of a treat, so this study had to use something  a little bit more appetizing. The birds were initially offered a tasty cube of bread or cheese from an open drawer. But inside a closed drawer, they could  see the preferred treat…mealworms.

The researchers varied how long  that drawer would stay closed, between five seconds and  five minutes and 20 seconds. And both humans and birds waited. In the end, all 10 jays were able  to exert some level of self-control and hold out for the mealworm, although  some did way better than others.

For example, there’s a female  named Jaylo, like JAYLO. She was capable of waiting as long as  she needed to to get her mealworms. Meanwhile, the two most impatient jays  could not wait longer than 20 seconds.

They also had the jays perform several  tasks to assess their intelligence from an ecological perspective…basically,  how good were they at applying what they learned about their  environment to change their behavior. And in general, the jays that performed  better on these intelligence tasks were also better at waiting out  the timer for their mealworm prize. That makes this study the first to demonstrate a link between self-control  and intelligence in birds.

And hey, maybe one day we  will learn that bumblebees have some self control of their own, too. Self control is great and all. But if you get swept up in a hobby like  pin collecting and you just can’t control yourself by buying every pin in SciShow  Space collection, that is also great!

These pins make you happy and they  support SciShow, so it’s a win-win! The concern is that you would need a  place to put all of those awesome pins. And that’s the problem we have solved  with the new SciShow Space pin board.

It has a cool design of the solar system,  and you can put all of those pins, which each represent a different spacecraft,  where they actually exist in space. You can find it at dftba.com/scishow. And for all of you non-pin collectors  out there who are just as eager to support SciShow, you can also  do that at patreon.com/scishow.

Thank you all so much for your  support and for enjoying this episode, which I did a lot. I hope you liked it as much as I did. [♪ OUTRO]