Introduced Theba pisana
snails aestivating on a row of fence posts in Kadina, South Australia
Aestivation, also spelled estivation in the USA, is a state of animal dormancy.
It is somewhat similar to hibernation. The animals are inactive and have a lowered metabolic rate. The state is entered in response to high temperatures and dry conditions. Lungfish have been doing this since the Devonian period. It takes place during times of heat and dryness, the hot dry season, which is often but not necessarily the summer months. A wide range of animals aestivate, including the Nile crocodile and many snails and lady beetles.
Invertebrate and vertebrate animals are known to enter this state to avoid damage from high temperatures and the risk of drying out. Both land- and water-living animals can undergo aestivation.