system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why some insects hold their position for hours?, what are they doing or not doing?
gpt
Conserving energy. Life is a struggle to maintain a balance of energy in/energy out, and many animals spend much of their time doing absolutely nothing until they need to eat again. 

Snakes, for example, may only eat once every few weeks and spend the rest of their time not doing much of anything. Other species, like hummingbirds, need to be moving around looking for and consuming food almost constantly to stay alive.