Guinea pigs tend to give birth overnight, so you might have a pleasant surprise one morning when you see the litter tucked under the new guinea pig mother! Hopefully if this is the case, there haven't been any complications during the birth of the guinea pigs.
When a guinea pig gives birth, she will normally give a very obvious and unique grunt which may last a few moments. The sow will put her head between her slightly spread legs when the litter is on it's way. She will put out the new guinea pig with her teeth.
You might see the guinea pig arrive into the world in an amniotic sac. This is normal, and the new mother will normally make a concerted effort to break it for the new guinea pig to emerge and take their first breath!
Once the new mother is happy that all is well with the new addition, she will relax somewhat, and lick her baby all over to clean it.
Sooner rather than later, the sow will experience more contractions and the next new born makes it's way into the big wide world. Guinea pig litters are normally born fairly soon after each other - it's hard work for the sow! A double birth can happen - where two babies pop out at the same time. Things can get a bit tricky here for the mother as she has twice the work on her hands. The baby that comes out second may not get attention until the mother has finished with the first.
Female guinea pigs are very organised and methodical during the birth process.
Most guinea pig births aren't full of complications, but helping out can sometimes save lives. If the new mother doesn't seem to have time to attend to one of a double birth, you can pick up the baby and pop the sac using your finger nails. If the baby gets to it's feet and gives a little cough, then all is probably well, and the mother can take over.
This isn't too complicated. Baby guinea pigs will suckle from their new mother for around 4-6 weeks from their birth. They will also have the odd nibble at the same food their mother eats from only two days old.
Male guinea pigs can go through puberty at 8 weeks old. For that reason it's strongly advised to remove them from the rest of the gang at around 6 weeks for obvious reasons!