1. Females become sexually mature at about 6 weeks and
males become sexually mature at about 8 weeks.
2. Mate one male mice to 1-3 females in a cage. Don't mate more than one male
since males will fight each other.
3. If timing of mating is needed, mate one male mice to 1-3 females overnight, and then
separate the male and females next morning.
4. Check virginal plug (hardened semen blocking the vigina, remain in place
for about 12 hours after mating) for successful mating.
5. Females (one to two) can also be kept with the male as a "family".
6. Females may mate again immediately after giving birth.
Check for pregnancy
Pregnancy can be detected at about 13 days after successful mating.
Check for the swelling of the mother's abdomen or an increase in the weight.
1. Check neonates for white stomach 24 hours after birth. If the neonates
are not showing white stomach, the mother is not producing milk. The neonates
need to be cross-fostered to a lactating female or the pups will die.
2. Never touch neonates with bare hands. Your scent may cause the mother to abandon the litter.
1. Litters should be weaned (separated from the mother) at 3-4 weeks.
2. If the mother is preganant, pups should be weaned before the birth of next litter.
Newborn neonates could be trampled by older pups.
3. Males should be housed individually at about 5-6 weeks.
As they mature, they become aggressive and may kill each other. Males that have been housed
together before sexual maturity will fight less.