How old are your chicks?
I'm a big fan of providing "enrichment" (as the zoos label it) for animals - species and age appropriate things to do, explore or eat are great ways to do this. It isn't "necessary", but anything I can do that will improve the quality of life I can offer the animals I am privileged enough to look after is fair game.
Providing structures for them to explore, climb on, etc is a great place to start. Introducing anything new to their environment will prompt curiosity - and while they may initially be suspicious, it doesn't take long for them to start hopping on/off, climb up /down, etc - especially once the first chick makes a move as the others don't want to miss out on whatever is going on. You can introduce, allow play and then remove so the novelty of that item doesn't fade as fast - rotating a few different items.
As for food - are you currently offering your chicks grit? If not, stick to chick starter/grower feed only. If you want to add "treats" to their diet, you need to provide grit first. Once you have the grit in place, you can start offering a variety of treats to supplement their starter/grower (but keep in mind they are just that, treats - they should be the "sprinkles on the cupcake", not the bulk of their diet). There are several threads that list treats for chicks here on BYC
