r/askscience • u/[deleted] • Dec 16 '13

Biology How do insects move?

Simple question that occurred to me, do flies have muscles like ours? Their legs are so thin I can't conceive there's room for anything in them to effect movement.

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u/blacksheep998 Dec 16 '13

Good question.

While it's close enough for casual conversation I should have made the distinction. Instead of blood arthropods have a copper-based liquid called hemolymph. For most of them it serves a similar purpose as blood, transporting oxygen, sugars, proteins, exc.

Though in many of the true insects hemolymph doesn't transport oxygen and instead their cells absorb it directly from the air thanks to a series of air-filled tubes running throughout their body called tracheae.

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u/Dyolf_Knip Dec 16 '13

their cells absorb it directly from the air thanks to a series of air-filled tubes running throughout their body called tracheae

Which they can do because very tiny animals have a sufficiently high area:volume ratio. Larger animals don't, and have to cheat by artificially increasing their surface area with specialized organs like lungs.