I was bitten really bad by my TAG coco when i was training him , bearing in mind he had never been taught to step up in 5 yrs , the first time i just let him bite me and he bit right through the skin that is the worst bite i have had , a few nips here and there , but worth the effort as I ask him for kisses and he kisses me every time with a enjoyable clicking sound . Now to train my 10 mth old congo ive had a few nips but not as bad my first .