Ferrets who are in heat do not bleed like dogs. Their vulva swells and they can have a clear discharge. If they are having any other color discharge a vet visit is in order. Jills will come into heat once or twice a year on average. Once being in the spring and the other being in the fall. They will typically come into heat after they are a year old, although there are some that have come into before that time. Jills who are not bred or falsed will develop a fatal disease known as aplastic anemia. Most pet store ferrets have been spayed and you don't have to worry about this. However, it has been shown that some spays have been botched and you need to go to your vet to have it properly taken care of. As far as the aggressiveness of the hobs. Are these new ferrets being introduced? Smelling of the bums is normal...it is how they smell each other scent. The dragging around of the neck is also normal for new ferrets. It is how they show dominance and establish a pecking order. They also will play by biting on the neck and some squeals can be heard. However, if you say this is going beyond rough, then separating them is in order. Aggressiveness can also be a sign of adrenal disease as well as a swollen vulva after spaying is done...although other signs should be evident as well. Sara Hamilton Leizel's Weasels [Posted in FML issue 4538]