Not eatting Hay

I'm kinda of concerned with my guinea pig's hay consumption. He really only nibbles on this hay or jumps in it, but doesn't really eat it like I have seen other guinea pigs eat their hay. I got one of those bird feeders that you put those fat cubes in (I forget what it is called >.>) to put his hay in. Originally it was just sitting on the floor of the cage, then I found he was using it as a bathroom instead of a table. I tried semi-hangin it on the side of the cage using the remain side to prop it up so it is angled and he can't sit in it. It worked to the point of not going in his hay, but he still doesn't eatting it with any regualrity. He is only 1-2 months old, does he not know any better to eat it full time? Will he grow out of it? Should I be using differnt hay?