Whether you planned for babies or unintentionally brought home a pregnant female from the pet store, when a litter arrives it's crucial to sex and separate the baby hamsters as soon as feasible to avoid hosting even more litters. You'll need to wait at least a few weeks to identify male baby hamsters, but begin checking as soon as the babies are weaned. If you can't be certain whether you have a boy or a girl, keep checking or consult your vet.
Wait until your baby hamster is several weeks old. If you try to identify a male baby hamster before that time, the testicles and other signs may not be obvious and you may mistakenly identify the hamster as female.
Hold your baby hamster in the palm of your right hand. Place your left hand around his body and gently flip him over so his back is now in the palm of your left hand. Some hamsters may become upset when you flip them over. If your hamster shows signs of stress, call it a day and try again tomorrow. Alternatively, place an uncooperative baby hamster in a clear plastic tube or box and hold it over your head to get a good look at the baby's underside. It is not always possible to hold a hamster still on its back without stressing it out.
Look for testicles. Syrians generally have more noticeable testicles than dwarf hamsters, according to Hamsterific.com. You may need to gently feel for lumps if your hamster is very furry.
Check for scent glands near the belly button of a baby dwarf hamster. You may or may not be able to see this -- and not seeing a scent gland does not mean your hamster is female.
Feel for nipples on your baby hamster. Female hamsters have a row of nipples on either side of their tummy. Locating these rows of nipples means your hamster is not a male.
Measure the distance between your hamster's anus and genital opening. Openings very close together likely belong to a female, whereas openings farther apart indicate a male hamster. Having multiple hamsters to compare simplifies this identification measure.
Small hamster image by Vedmochka from Fotolia.com
Sandra Ketcham has nearly two decades of experience writing and editing for major websites and magazines. Her work appears in numerous web and print publications, including "The Atlanta Journal-Constitution," "The Tampa Bay Times," Visit Florida, "USA Today," AOL's Gadling and "Kraze Magazine."