Wild animals run for fun
Do captive mice run in their wheel because they are neurotic and stressed? Or is it a natural mouse behavior? Well, it turns out that if you put a running wheel out in the wild, the mice will come. And they will run. Turns out frogs and other animals will join in too. Pretty cool. Read more about the study here, or download the open access paper here.
Note: this does not "prove" that mice in captivity aren't running in a wheel due to stress!
Best video from this story: a slug in a running wheel. Please watch.
Using robots to learn about animal behavior
Even though the Senate made fun of the robo-squirrel study (citing the NSF funding it received as a waste of tax-payers' money), robots can be useful in working with animals to study social behaviors. Because the robot's behavior can be controlled (unlike another animal's behavior), you can use them to measure responses to specific visual cues.
This study was a little funny as it looked at chimps responses to a robotic doll, and the chimps were a bit afraid of it at first. They did start interacting with the dolls quite a bit, and especially when the doll imitated them! You can read more about the study here.
What are the effects of living upside-down?
Ask a sloth. They can't vomit and they poop once a week. That upside-down lifestyle frees their front paws for lots of grooming, but can place other stressors on the body that scientists are still trying to figure out!