While the concept of spaying and neutering hedgehogs has been tried in a couple of places, the fact that their sexual organs are located so far internally, in what is a small animal to begin with, makes this an extremely dangerous and delicate operation, even in the hands of those who know what they are doing. In effect, it may not be a worthwhile risk.
Unfortunately, hedgehogs don't come with blue or pink tipped quills to make determining the sex of your pet is an easy job. Some breeders add a spot of non-toxic paint, etc., but even that's no guarantee. There have been more than a few people who brought home "male" hedgies, only to have them give birth to a litter a short time later. In fact, it can be downright difficult, to figure out the sex, unless your hedgehog is willing to let you hold him or her on its back long enough for a look at its tummy.
If you can't get the hedgehog to unroll enough while being held in your hands, you might try viewing the hedgehog's belly from the underside of a piece of glass or plastic the animal is placed on.
For male hedgehogs, the sex organ, or penal sheath, is located about 2/3 of the way from the nose to the tail (along the tummy), and looks like a large belly-button.
In the female, the sex organ is located all the way down the tummy, directly adjacent to the anus. The female will also have a row of nipples along each side, below the quill line, within the soft tummy fur. These are often hard to see, but do show as small pink spots.
In babies, it can be difficult to tell sexes, without experience, due to the small size causing everything to be together. Beyond the baby stage, the rule of thumb is that if you look, and can't tell for certain, it's probably a female, as males are usually pretty unmistakable.
Hedgehogs as young as 6 weeks old can mate. If you have babies, remember to separate them before this age.
The one time that hedgehogs completely abandon their silent ways is when it comes to mating. This is particularly true of males who will often end up sounding like a video game gone wild with an amazing series of squeaks and chirps as they vie for the favors of the lady.
The European hedgehog typically begins breeding in the spring and may have a second breeding in the fall.
The African species breeds year-round. The gestation period is 34 to 37 days. Litter size ranges from one to seven pups, with an average of three to four. At birth, the spines are very soft, a new set of stiff spines appear at about 2 to 3 days and their eyes will open at 14 to 18 days. Weaning occurs at 4 to 6 weeks of age.
Immunity in the newborn is acquired through the colostrum (first milk), and it is therefore advisable to leave the young with the mother for at least 48 to 72 hours. Vaccinations are not recommended.