>>New to breeding rats<<

[Lord Sorril]

1: When can my female breed after birth? I know right away, but ideally how long should I wait her out?

10-24 hours after giving birth the female rat can conceive again (not after 24 hours though) This is called post-partum estrus. A post-partum estrus conception usually has a gestation time period of around 32 days. If you do not take advantage of the post-partum estrus you will have to wait 28-29 days before the female can conceive again.

2: Can the male rat safely be left in with the female and her babies? (so say in the event my girl gives birth over night and the male is still in there)

Depending upon your strain: Some males do not interfere with the babies, and others will may harm them. If you are vigilant in your observations and you have a large enough population: you can selectively breed non-aggressive males by culling those with disagreeable behavior.

3: Should the female always be housed away from her future cage mate after birth to prevent the other rat from attacking the babies? How common is that?

Depending upon your strain and cage size: Some female rats make better mothers than others. A good mother will defend her offspring, however, if she has very little cage space the second female may eliminate her litter. Some female rats will share litters in a big pile without conflict. Again: selective breeding can remedy disagreeable behavior.