There's this thing on my engine.....

I am not sure what this thing is for, but the squirrels (or rats) were storing dog food in it.

It is plastic. It is fixed to the timing belt cover. It is connected to the air intake. It looks like some sort of cyclotronic blower housing, except that it has nothing in it (except dog food). It doesn't appear to have any useful purpose, but I am pretty sure that if I take it off, it won't be there anymore.

Any ideas?

1996 Geo Metro 4 cyl Std. Trans

Yes, it's the resonator for your air intake. If you remove it, you will hear your intake more, particularly at certain RPM points. If you can fix/repair it, your intake will stay quiet.

There's no harm in removing it, however.

-Pink

That was my very first Metro "mod" I did ;)
Removed everything except the air filter housing.