Seperating a Male Degu from Females

A degu we bought at the age of 6 weeks is now 11 weeks and the woman left us some instructions on when to check his sex and when to seperate if he is male.

It's approaching that date and he is male.

We aren't able to get him neutered yet, so we wanted to seperate him before we found a vet and have some money together (we're moving house at the moment, so money is tight).

I've uploaded some pictures of our cage, as you can see it's very large. Our 11 new borns (that will be around 1 week old) are all snuggled at the bottom with mum and two other female degu's.

Since the babies have been moved from the top floor to the bottom (something which the mothers did earlier today) they all spend the majority of their time down there.

My question is, until we get this vet and money sorted, could we keep the 11 week old on the top floor? It's going to realistically be until the end of September, and even though he would be alone, he has lots of attention from us and loves a run around in his ball too, so he would be very active.

We have a safe way of blocking the exit (a cooling slab that we use sometimes to seperate them when cleaning).

Or would it be easier, and calmer, for the Degu to buy a smaller temporary cage? The problem with that is finding one, as I said, money is tight. I've had a look on Craigslist and pre-loved, and unfortunately no cages are being given away - at least not with more degu's included. And I think 15 is our limit.

He is very hyper since his mother and sister gave birth, I know they are most fertile at these times, and so I think that coupled with the smell of that and the fact that he's growing up is confusing him!

So, any suggestions on whether seperating them cage wise is best...or a different cage completely?