Platypuses are among the world's most unusual mammals, and among the most difficult to keep in captivity. Very few zoos worldwide successfully maintain platypuses outside of Australia.
Platypuses are monotremes — egg-laying mammals — with electroreceptors in their bills that detect weak electrical fields from prey. They require running water systems that mimic burrow entry; static tank water causes disorientation and reduced welfare. They eat up to 20% of their body weight in invertebrates daily; food provision is extremely labour-intensive. Water temperature must be precisely maintained. Very few institutions outside Australia have successfully kept platypuses; the Healesville Sanctuary in Victoria has the most successful program. The platypus is classified as Near Threatened in Australia, facing habitat degradation and climate impacts.