Why are some hamsters aggressive?

Question

well i went to a market, and saw this man selling hamsters. he put them in two aquarium tank. and the one on the left is normal, very normal. but those in the right tank are not. they are soooo aggressive the seller even need to wear a glove to pick them up, and also they squeak sooo hard i wonder what happened to those aggressive hamsters. oh and they are all baby hamsters.

Answer 1

some breeds are more aggressive but if handled young get tame easily these wer not handled also hamster like to live alone except dwarfs

Answer 2

They're ANGRY. Angry hamsters are serious business.

Answer 3

I think it depends on the breed.