Hay-nger Strike

Wow, I'm so friggin funny. That title...

Anyway, my guy Pedro kinda stopped eating hay. He's been acting normal. He looks about as normal as he can get. I don't know what happened. I know hay is essential in their diet. Is there something that might have caused him to stop, and maybe a way to get him to start eating his hay again? Has anybody been through this before?

Anything you can suggest that might work, I'm willing to try, just so long as Pedro wouldn't be put in danger...

Hay-nger Strike