Platypuses are largely solitary.
When not foraging, individuals normally spend most daylight hours tucked up inside an earth burrow in the bank of a creek, river or pond (Grant, 2007). Some individuals have been found resting in accumulated stream debris or in low, dense vegetation (IUCN, 2009).
While foraging in water, the platypus stores food in its cheek pouches which lie beside the horny grinding pads in the mouth. This food is then masticated once it rests on the surface (Grant, 2007).
Platypuses are known to carry a number of parasitic animals in the wild, including their own unique species of tick, Ixodes ornithorhynchi. This tick is thought to transmit the protozoan blood parasite Theileria ornithorhynchi but this is usually regarded as harmless, normally infecting only a low percentage of the red blood cells.
Platypuses suffer from a fungal infection (Mucor amphibiorum) found in amphibians of mainland Australia. To date, this infection has only tentatively been reported in a few mainland platypuses but in parts of Tasmania it has resulted in a condition that causes severe skin ulcers. It can invade other tissues, including lungs, and has led to mortalities in certain populations (Grant, 2007).