Although frogs have lungs, they absorb oxygen through their skin, and for this to occur efficiently, the skin must be moist.
Green Tree Frog © Sophia Volzke
The common Australian Green Tree Frogs are often found around water sources inside houses, such as sinks or toilets. They are known to occupy tanks, downpipes and gutters, as these have a high humidity and are usually cooler than the external environment.
Eggs are laid around lakes and swamps where they hatch after about a week to continue living in the water as a tadpole for another 6 weeks. After that period, frogs undergo metamorphosis within 24 hours to develop into the adult form where they develop limbs to leave the water.