Both male and female copepods can mate to produce what's called a "cyst." These cysts are egg-like structures that protect the offspring until they're ready to hatch. However, female copepods can produce these cysts on their own. These cysts may hatch right away, or some may fall to the bottom of a water source and remain until they're ready to hatch. If a body of water dries up, the cysts will remain buried until rain or flooding introduces water back into the environment. These cysts can survive for seemingly endless amounts of time, hatching whenever water is reintroduced.