While most females of a species are the most common primary caregivers, in some species (for example, the seahorses) males are the primary caregivers for their offspring. Male parental care may be as simple as defending the nest against potential predators, or as time-consuming as providing food and the shelter of their bodies for young hatch-lings. Other species have no caregivers—for example, when it comes to guppies, no parental care by either sex is provided.