I don't think live mealworms even make that good of bait for bass (they work good for bluegill, perch, trout, etc though) so I doubt some crunchy bird food is going to interest them. Plus, mealworms are like an inch long... I've seen an 8" bass eat minnows over 4" so I would look into some bigger lures.
The hook size varies on the time of year that your fishing in. Water temperature, water clarity, and time of the year has almost every effect on what is best to use and what size hook is ideal. Just because they have a very large mouth doesn't mean a big hook would work anytime.
If you really want to target bass, I really suggest you to stock up on some bass lures. Nothing expensive or fancy at all. Just some senkos and some small swimbaits/crank baits with some spinner/buzz baits. Top water during morning and evening is extremely effective also with poppers and so on.
If you want to use actual bait for bass fishing. Best to go with live crawdads and live minnows. Nothing else can beat it, that is all I got to say.