system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 How do insects climb walls and other flat surfaces and stay attached?
gpt
There are two ways insects are able to hold on to surfaces; tiny hairs and adhesive pads.

Many insects like common houseflies have a large number of very tiny hairs on the bottom of their feet. They can use these hairs to hold on to microscopic bumps in surfaces. The hairs work pretty much like a human rock climber's hands and feet but the difference is that they have thousands of these hairs and all of them combined are enough to hold the tiny weight of the insect.

Some insects, like grasshoppers, have tiny adhesive pads on their feet. Different insects have different types of adhesive pads but they too usually contain numerous hairs and secrete an oily substance that causes the tips of the hairs to adhere to the surface similar to how a wet shirt adheres to our skin.