Entomology (Study of Bugs)/Why do flies fly?


Dear Sue,

My six-year-old son is going through a rather inquisitive phase: some of his latest questions include 'Why do old people wave slower than young people?' and 'How much water would an ant need to take a bath?'

The other day he asked me why flies have to fly, and I'm darned if I know the answer. I don't like fobbing him off with half-hearted responses, and was hoping you could shed some light on this question. I can tell him HOW flies fly...but WHY do they have to fly in the first place?

Can you help?

Flies have to fly so they can (1) get from one place to another to find food, find mates, and find a place to lay eggs, and (2) escape from predators quickly.

Flies eat liquefied rotting food, and the maggots also eat rotting food.  Once the rotting food is gone, if they couldn't get to someplace new, they would starve.  On their short little legs, it's hard to walk far.  Flying also allows them to go to places they couldn't reach on foot, such as fruit hanging in a tree.  

Entomology (Study of Bugs)

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Sue Kayton


Silkworm expert. Have raised them as a hobby for 20 years. I do not identify unknown insects.

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