Question about my dog while biting

Hey plz i want to ask you about my maltese, sometimes she became so hyper especially when she wants to do her needs and she starts to bite my hands and sleeves and howl plz tell me what should i do.
And second question about her eye: i see yesterday brown hair under her eye (i always cut the brown hair) but now not only the hair it seems like the skin under eye is brown( a little bit not a lot)