Fruit flies do not bite humans but are they still dangerous? You may have seen red Fruit flies can potentially create serious health risk in your home. Due to the. I can't even get a photo of them. I used to think they were tiny little black fruit flies, but these critters like to bite! I've seen them in my kitchen. Do Not Feed on Blood Although fruit flies quickly become nuisances when they enter homes, the insects do not bite humans because they do not feed on blood.