system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do many tires come manufactured with hairs?

I've noticed it since I was young, but I guess I never questioned it until now -- most tires come with bits of rubber sticking off that look like tiny hairs and I'm wondering what the purpose of those hairs are.
gpt
When you're injecting rubber into the mold you're going to have air that's going to need to be displaced, right? And you can't exactly purge air from every nook and cranny easily. You can keep pushing rubber in but air compresses really well so you might end up with pockets that cause deformed tires. 

So instead you put little extra vents for the air to go into at regular intervals all over the mold. The air will compress within these vents instead, a little rubber will go up these little vents as well, et voila, hairs on your tires when they come out of the mold.