According to Dr. Klaus Reinhardt from the University of Sheffield U.K.,they found that females do this by lowering the metabolic rate of sperm, so it can survive in their bodies almost indefinitely.
In one extreme example, biologists have shown that queen ants fertilise their eggs with sperm they’ve stored for up to 30 years. Normally, once it’s outside the male’s body, it doesn’t survive for long. The findings could explain why, in reproductive medicine, sperm samples aren’t necessarily the best way to predict if someone can father children or not.