I imagined the topic heading referred to the Entertainment WE get from watching our chicks in the brooder. Oh, and watching the grown up chickens in their runs. I love to watch the babies scratch around in the litter, looking for feed that got away from them. Or do the dust bath thing!!! Adorable and hysterically funny at the same time.
Treat time is entertainment for them - give 'em some mealworms and watch the action!
I do have an empty toilet paper tube in the brooder with them. They like to mess about with it, poke their heads inside the tube, stand on top of it like a log-roller, kick it around.
There's also an old wooden dowel thing that used to be a hanger on the wall for towels, or bathrobes, or sumpin' like that; I've put it in the brooder as a "roost" for the chicks. They enjoy roosting on it like Big Chickens. During the day, it's a great jungle-gym type thing for them.
Other than that, chicks really don't need toys to "enrich" their little lives whilst in the brooder. They're not going to be in there forever, like caged birds.
And they're their own entertainment, as another poster has mentioned.