Ok, I'll give everything a rundown of what I think.
Wasps/bees - Those bright orange/yellow marks are there for a reason, the black stripes give it more contrast. Most animals avoid them by instinct since those colors mean "I can bite back!" Of course some animals will take advantage or just don't care.
Slugs/earthworms - I guess these are just personal preferences, I've seen mine eat some before, but they hate the slime. If yours don't like slugs or worms, consider yourself lucky. There's an array of parasites that use these as hosts, until something like an unsuspecting chicken comes along and eats it and in turn gets infected.
Ants - Ant brood is a different story, I'm sure most chickens love these. adult ants, not so much. It's either the nip of the mandibles, the formic acid, or the sting. For most chickens, it's not really worth it for something so small.
Lady bugs - Once again, the pretty litle lady bugs have those bright contrasting colors for a reason. Between their legs, or "armpits", they secret a fowl tasting/smelling liquid that no predator would want in it's mouth.
Catterpillars - Though hornworms are often a big hit, anything with hair is a no go. Those are ment to sting or irritate skin, and even for a human it's not fun to touch one. Let alone stick one in your mouth!
That's all I got for now.