|MadSci Network: General Biology|
In the general sense of the word, bugs definitely do sleep. They don't close their eyes, but their rates of oxygen consumption do drop at various periods during a 24 hour cycle. Does it matter when? You bet it does. An insect has various needs; they have to find a mate, find enough food and avoid predators in the process. Thus, every insect has their own time of day or night when sleep is appropriate for them. Moths tend to have a period of inactivity during the day. Like many other insects, they will find a place of refuge, such as the underside of a leaf, to avoid predators. For dragonflies, who hunt and court mates by sight, there is no point remaining active at night.
You may find more information on this subject in a book called Insect Photoperiodism by Stanley Beck.
Hope this helps
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