When ectotherms need to warm up, they may bask in the sun, orient their bodies towards the sun to expose the greatest surface area, increase their surface area by e.g. spreading their wings, or press on the warm ground in order to absorb heat. Metabolic heat can also be generated by contracting muscles or vibrating wings.To cool down, ectotherms need to shelter from the sun, hiding under rocks or in cracks or burrows, orient their bodies to expose the minimum surface area to the sun and may immerse themselves in water or in mud.