eli5: How do insects just know what their designed to do?


Legitimate question from my little brother; how do insects like mosquitoes, ants, and bees know what their directive is from birth to death?

In: 3

Simply genetics: their DNA codes in such a way they feel an incentive to perform their roles.


It’s called [instinct](https://en.wikipedia.org/wiki/Instinct), and we have it too, from birth. A baby knows what to do with food (eat, chew), is very much attached to his or her parents and reacts emotionally to seeing and interacting with them (as opposed to other people), interacts with objects in the environment, etc.

A big part of instinct is having reflexes. Reflexes are actions that you take without thinking; pulling your hand away from something hot, holding your breath under water, etc. Reflexes don’t require a complex brain, the behavior can be enacted by just a few neurons, such as what an insect may have instead of a “brain”.