Integrating New Ferret

Question
I wrote to you a few months ago for advice on integrating my new ferret to the group. Erryl is a 18 month old (spayed) jill and Fang and Cosmo are 4 year old (neutered) males.

Lately Cosmo keeps scruffing Erryl. She is scared of him and squeals and hisses at him when he comes near. I feel like Erryl is never going to get on with other ferrets. She doesn't seem to know how to interact and play with the boys. I have had her for 5 months now. Please could you give me some advice to improve the situation.

Answer
A lot depends on why Cosmo is or seems to be picking on her.  At 4 years old, he could be showing signs of adrenal which present in a behavior change - usually aggression.  On the other hand, he may be acting like this because he can.  I assume they are all kept together at all times because any separation can make the behavior worse.  Certainly have Cosmo checked out at the vet and make sure they are being kept together with places for Erryl to hide.  We use a small plastic tub with a lid.  Cut a hole and place a hose (dryer etc) in the hole.  Erryl can go into the tub and protect the small opening from Cosmo.