Why is hedgehog easy to get pregnant?

On the one hand, hedgehogs are smaller and have better reproductive system. On the other hand, hedgehogs are very fertile and can get pregnant every time they mate successfully.

Hedgehogs are short and fat, with sharp claws, small eyes and short hair. The body is covered with short and dense thorns, and the head, tail and abdomen are covered with hair. The mouth is pointed and long, and the tail is short; There are five toes on both front and back feet, and a few species have four toes. When frightened, the whole body pricked upright, rolled into a thorn ball, and the head and four feet were invisible.

It lives in the bushes, can swim and is afraid of the heat. Widely distributed in Europe and northern Asia. Hedgehog is a small mammal with a body length of only 25 cm, and the adult hedgehog can weigh up to 2.5 kg. The back and side of the body are covered with thorns, and the head, tail and abdomen are hairy; Long and sharp mouth, small ears, short limbs and short tail; Both forefoot and hindfoot have five toes, and a few forefoot have four toes; When curled up in a ball, the head and four feet are invisible.

36~44 teeth, all with sharp teeth, suitable for eating insects; There are thorns all over the body except the stomach, and the short tail is also buried in the thorns. When frightened, its head bends to the ventral surface, its body curls up into a ball, wraps its head and limbs, and stands up with thorns to protect itself. Unlike porcupines, hedgehogs don't lose their spines. Hedgehog's nose is very long, and its sense of touch and smell are well developed. Its favorite foods are ants and termites.