What are these little red bugs?
Im guessing you are seeing mites. Box elder bugs are black and red, and yes, harmless to your furry friends, but they are at least 1/4th to 3/8th inch long.Mites are tiny.Teeny tiny, like the size of pinheads or smaller.I dont think the little bright red mites would pose any problem to the rabbits, but mites in general should be avoided or exterminated.They most likely wont kill an otherwise healthy rabbit, but will cause irritation to them, especially inside the ears, and they multiply rapidly. If you are treating the rabbits now, just follow the instructions with the pesticide and if anything looks like its getting worse,consult a vet. Google box elder bug, and see if that is the bug your thinking of, but since you said really small, and you didnt mention that the bugs fly, I doubt you are talking about box elder bugs.