OK so background:

3 boys - neutured, 1 year and 2 months old. Live in a huth and play in a run in the garden. Never bite, really friendly and well behaved but obviously very energetic and won't keep still.

Recently I discoveres 2 girls were in need of a loving home so I thought I'd give it a go.

2 girls - 3 years old, spayed.

When we first introduced them, it was on neutral ground and within minutes the boys were laying into the girls. There was poo and wee and skunking. The girls were terrified.

So we took them home and the girls are currently living in the run. When the boys need a play we swap them. So the girls get to spend some time in the hutch.

We've given them all baths to get rid of any old smells, we're swapping the ferrets, the bedding, doing everythyig we can.

However today I accidentally put on the girls within reach of the boys. They pounced, there was screaming, biting and some pretty nasty tooth marks. I'm really worried because it's been 5 days with no improvement. The girls are stressed and don't even fight back, they just freeze yet the boys insist on trying to kill them.

Is this going to get better with time or am I just wasting my time? Has anyone got any tips to make this transition easier?

At this rate I'm going to have to give the girls up and I don't want to do that.

Ferrets can be very territorial. I have noticed this especially with European ferrets. They are a bit more "wild." Ferrets are very intelligent animals and if they decide they don't like someone(other ferret) or feel threatened by the new additions they are going to be stubborn and defend your home. Keep watching their interactions and if the fighting doesn't stop it'd probably be best to find them a new home. 

I have had Captain and Morgan for over 3 years and Pirate will still NOT accept them. If they are all out together he tries to KILL them!!! So we have 2 separate cages and 2 separate play times. Even then at times they will try to go at it through the cages Its the best we can do

I have two play groups.  My two privately bred ferrets decided they didn't want to be housed with the others.

They are out to get the others....you can see it in their eyes, body language and they will be very vocal.

It's something you need to taken in consideration when you bring in another ferret into your household.