Do they bite?
Sonic: will bite if asked! otherwise doesn't get much mileage out of it personally
Tails: bitey. chews on pencils and pens and tablet styluses. has bit a badnik before. will continue to do so as long as he has baby teeth privileges.
Knuckles: raised by a magical space rock that taught him better forms of diplomacy. namely diplomacy with his fists, which are much less fragile. will nip at friends though.
Amy: absolutely not! she's no animal! people don't like biters. people don't like girls who bite. people don't like girls who bite. so she doesn't bite.
Shadow: Absolutely not. He's no animal. Scientists don't like biters. Scientists don't like weapons who bite. Sisters and Grandfathers don't like weapons who bite. so he doesn't bite.
Rouge: will bite if asked! otherwise prefers her "bite" to be more metaphorical.
Omega: yes. does not matter that he does not possess a mouth. the spirit is there and it is willing.
Cream: no!! biting isn't proper. mom taught better. chews on her fingernails and inside her cheeks though. doesn't know why she does it.
Vanilla: is the mom who taught better. chews discreetly and quietly on a piece of wood whenever stressed. hoping that cream doesn't imitate her. people don't like biters.
Big: not interested in biting unless it's the fish biting. or biting into a fish. both are good.
Vector: yes, often. one of his main weapons actually. unlike most of the roster, regrows his teeth fast. can and will bite a badnik again. too bad they taste terrible.
Espio: ninjas don't bite. he is a ninja. transitive property at work. (even if he did try to imitate Vector for a phase when he was younger.)
Silver: knows just how valuable teeth are, won't waste them on ordinary combat encounters. will bite if you try to steal his food. don't ask Sonic how he learned this.
Blaze: bitey when she was little, absolutely mortified by the thought of anyone learning this. but hey, it's hard to express your boundaries otherwise when your hands are bound in fireproof material, so she should cut herself some slack.
Eggman: no? what, who do you think he is? don't you dare think that the animals are rubbing off on him!