Animals getting into random fights

[Sinclair]

Hi, have you had this happen in your forts? My animals would start random fights with each other, usually resulting in at least one death. Once I had a massive brawl involving half the population that started with a dog biting someone. Another time I saw cavies savaging each other on the pasture, and in my current fort the ducks decided one day to start beating each other over their nest.

Is overcrowding an issue perhaps? Or is it caused by random animals having 'likes getting into fights' as part of their personality? A combination?

[Rat]

animals fight when they're overcrowded yes. if your pasture is too small they'll fight with each other. that massive brawl with half your population though sounds like a different bug entirely sometimes called the civil war bug.

[TPark]

Pretty sure Rat is correct and this is a result of overcrowding. I don't think I've ever seen a tame animal attack a dwarf (except when being gelded, LOL)

[Morkonan]

Originally posted by Sinclair:

...
Is overcrowding an issue perhaps? Or is it caused by random animals having 'likes getting into fights' as part of their personality? A combination?

It's definitely due to overcrowding.

You'll also see other issues, like animals out of their proper zone having fled the fighting between other animals.