How beetles breathe under water
by David Pescovitz from on (#T8WA)
From KQED Science:
Surface tension is the property of any liquid that describes how its particles stick together. In the case of water, surface tension is especially strong, enough to form a kind of film where it meets the air, whether at the surface or in a bubble...
If you're a bug the size of a paperclip... surface tension makes a difference. Harnessing it, some aquatic beetles carry the oxygen they need underwater in the form of a temporary bubble, sort of like a natural scuba tank. Others encase themselves in a layer of air and draw oxygen from it their whole lives.
"Nature's Scuba Divers: How Beetles Breathe Underwater" (Deep Look)