Sneezing is usually a sign of stress, most likely from moving to a different place. Make sure they don't have excess drainage from their eyes or noses. Keep the male and females apart until the sneezing subsides. They are also sneezing from the pine bedding. Pine causes respiratory distress and over time will cause liver/kidney failure from the oils iin the wood. Get the rats off of the pine if you do not want them to get sick. It doesn't matter if you have any left, get it away from them. Rats do not produce well if they are sick or in distress. Aspen works great and is just as cheap and easy to get.

Cages should be cleaned out at least once per week. If you are keeping the male in an aquarium as well, he will need to be changed out more often than the females because of the amount of urine he produces. Urine=ammonia=pneumonia. If you can smell the urine, then the rat is definately suffering the effects. They drink alot of water and produce alot of urine. Change the male's cage out at least twice a week if you want him to remain healthy and be able to breath without wheezing.

Plus, you will want to make that mix if you have any hopes in having good-sized litters and healthy, fat babies. The pre mixed crap does nothing for the mother's ever-growing nutrition requirements, and will result in stunted babies and small litters(plus underweight mom rats).

If you want the male to stop sneezing, just keep him away from the females, keep his cage very clean and NOT dusty(NO pine), feed him and leave him alone. If the sneezing gets worse, he is working to breathe, is wheezing or is gasping for air through his mouth, get him to a vet immediately. That kind of stuff can turn deadly very quick. All of the sneezing is just a mycoplasmosis attack. Myco is an organism carried naturally in a rat's body, that when the rat is stressed, decreases or impairs the rat's immune system, causing infection or other ailments to take over their bodies. That's why it is important to keep the stress level down and keep them correctly.

I think that is about IT AFTER the male stops sneezing and is back to normal "ratty" behavior, you can introduce him to the females, in HIS CAGE, not theirs. Females are pretty territorial and may fight with him, but if they are put into his cage, it is a new environment for them and they will be more curious of everything. The females come into heat ever 4-5 days, and pregnancy lasts from 21-23 days, sometimes longer. If you wait to breed the females again after the first litters are weaned, you will have larger litters and bigger babies. Breeding the female while she is still lactating and feeding a concurrent litter is very hard on her body, and you will not get the litter numbers or healthy babies you are looking for.

Hopefully that helped a bit, and if you have any other questions, ask.