Hi I have just brought my new Devon home and my other Devon is devastated and wont let anyone pat her . She just hisses at everyone and has gone for my daughter twice.This is out of character . My other two cats just hiss at him and growl when he comes near them. I have brought the Feliway Diffuser to see if that makes any difference at them moment the house is full of hissing cats. It is early days yet its only day Three..Everyone is hissing at each other..Can anyone suggest anything else that could help them..