First thing I would do is to stop trying to feed them in a seperate enclosure. Sometimes they can get sensitive any handling just before feeding.

Rats can be "bad", but it's not a common occurance. If you suspect the rats are bad, try a different supplier.

Your cool side temps should be closer to 78-80 degrees at all times. 90 degrees is too warm for a cool side.

What are you using to heat your enclosures and how are you measuring your temps?

Your Spider could be on a breeding season fast, but if there are no breedable females within smelling distance, I'd look for another cause of the problem.