system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why do some animals adopt a different species of animal occasionally?

I just watched the video of a cat "adopting" a squirrel that was separated from its mother. What makes some animals do this, despite normally having an instinct to, say, eat the squirrel and provide for its own young?
gpt
A lot of times, the instinct to care for its young is just an instinct to care for something with a shape similar to its young. Depending on the species, this is a pretty useful trait because looking after any member of its species' young is gonna help the species survive.

It just so happens that sometimes, that the "look after whatever looks most like a kitten" gene sometimes gets a bit confused and sees a squirrel and is like "eh, close enough".