I've been noticed that my 3 kittens are lacking hair in some bits of their tail. 2 of them have just a tiny tiny hairless zone, and the other one has several different spots that are lacking hair for complete. It doesn't look red or injured. I haven't seen them licking or biting their tails, they don't act like they feel hurt or anything like that at all.
I am a bit concerned though, I wouldn't like it to be contagious. I find it weird that is happening to the 3 of them. (Even though I noticed they had like a tiny scar when I first got them) They are a bit older than a month.
What could it be?