Congrats on your new ratties ..... if they are under 5 weeks old you might want to supplement their diet of blocks, and a variety of daily vegs with organic (or nonGMO) soy infant formula thickened with baby cereal as they are a bit young. I hope you post lots of pics
If you have access to a good vet with the knowledge and experience to safely neuter or spay rats, then please have them fixed. Only gas is used until after the surgery is over when an injection of Metacam is given for pain.
If you have a good vet with the ability to operate on pet rats safely, then neutering can be done at a younger age then spays, however, in my experience, vets want rats to be a certain weight/age before giving them anesthetic to be on the safe side. After a neuter, the boy is kept separated from intact girls for 2 weeks - some do 3 to 4 weeks to be sure) so that all sperm is dead.
Do not allow intact rats over 5 weeks old and of opposite sexes to spend time together as pregnancy can happen very fast
It is important to spay girls, if at all possible, for health reasons.
In terms of intros, if all rats are babies (under 12 weeks old) they can be put together as babies see other babies as playmates. If any rats are over 12 weeks old, then gradual intros need to be carefully done as the rats will see new rats as potential threats. If introing a baby to an older rattie, the baby needs to be at least 8 weeks old (10 weeks is safer)
For reasons to spay/neuter please see:
Why Spay or Neuter Rats?
For info on introducing rats as well as other important info please see our Reference Thread
REFERENCE Thread - Read Only