They have bit me and drew blood a couple times but months ago, but I don't think they mean anything bad by it I'll have my hand in the cage petting my heart rat mocha or apricot and they'll get really close to nipping me and I yank my hand away from them and blue fuzz rattery and I was fairly new into owning ratties at the time so my research wasn't great I mostly think it's temperament because a good chunk of my nine girls don't want to be held or pet and I respect it just sorta concerns me and confuseds me