Sea otters are well-known for using tools, like rocks, to break open shelled prey. But a recent study, done in collaboration with Aquarium researchers, sheds light on a fascinating detail: it's mainly the female otters that use tools for this purpose.
By using rocks or shells to crack open hard-shelled prey, female otters, who may have less robust jaws than males, can eat bigger prey without risking dental damage. This helps females get the high number of calories they need, especially when raising pups.
Female Otter: Here, just let me show...
Male Otter: I've got this, Sheila! I don't need your stupid rock!
Sheila: Fine, Kevin. Break your incisors. See if I care. *swims away*
The male otters are probably too busy chasing the female otters to bother with learning to use tools. When the aquarium first opened you all had a male in the otter tank, it was... not a pretty scene! Things calmed down a lot in there when the male otters were banished...