My rats, Sampson and Hollywood

Question
I have emailed you before with a rat question, and here I am again. My rats were in a 75 gallon tank, but a few days ago I got them a HUGE ferret cage with four levels and tons of ramps, small stairs, big tubes, and slide-like things .. but instead of using any of these things, they just hold on to the sides of the cage and climb up and down that way. Is this normal? Is it bad for their little feet?

Also, I have 5, possibly 8, new rats coming on Friday. They have all been together since birth and they are all boys. They are also coming with their own cage that is actually a large bird cage, transformed into a rat-safe home. Would it be bad to split some of them up and put them with the rats I already have?

Answer
Sorry for the delay.  Flu!!

Anyhow, sounds like plenty of room for the rats and yes, its normal for them to climb. Its in their nature.

As for adding more rats, be sure that they are quarantined prior to introductions for 3 weeks in a totally different air space.  

If you want to split them up later on, as long as they adjust to each other, thats fine.
I always believe that you should have just a small mischief of rats rather than a large one.