glass pipe question

I bought my first pipe a few days ago and I've never packed a pipe before, I've always rolled or took a hit from my friend's bong. There is a small hole at the bottom of the pipe. What is it for and how can I cover it up so my weed doesn't fall down it?

You can get a screen, but I never use one, put some bigger chunks at the bottom, but not too big.

i actually use screens, i use metal ones do to their cheapness if lost and ease.

but if im out, or am too lazy to get one then i put a good sized little bit over the hole, then proceede to put crumbs, but not dust around that piece.

i would recomend screens, either glass or metal because it sucks to get a cherry in the back of your throat, and sometimes the hole is rather large and will allow the blocking nug to actually get sucked into and caught in the bowl without being smoked yet.

screens or some call em pipe gauze