When cats are happy, they may squeeze their eyes shut.
10
The Hercules beetle, despite weighing only 100 grams, can lift 8 kilograms, making it one of the proportionally strongest animals in the world.
8
Sergeant Stubby was the only war dog to be promoted to sergeant through combat in WWI. He saved his regiment from surprise mustard gas attacks, found and comforted the wounded, and even once caught a German spy by the seat of his pants, holding him there until American Soldiers found him.
16
Meysi is one of the world's smallest dogs, measuring in at just 7cm tall, 12cm long, and weighing a meagre 250 grams (only slightly heavier than a hamster!)
11
In 1918, a homing pigeon saved over 190 American soldiers by delivering a message to nearby support despite having been shot through the breast, blinded in one eye, covered in blood, and with a leg hanging on by just a tendon.
22
Gorillas can catch human colds and other illnesses.
205
Using a remote-controlled camera, biologists caught dolphins getting high by sucking on puffer fish. They were even caught passing the puffer fish around.
23
When dragonflies mate, their tails form a love heart.
22