Mine get tremendous entertainment from pecking at suspended mealworm cake (suet cake that does NOT have the lard) & a cabbage ball, I like this one as the cabbage lasts a bit longer & doesn't end up on floor.
Treats are a very easy way to keep birds distracted, but my entertainment suggestions aren't food/treats, and that's deliberate. I try to minimize treats to ensure the birds are mainly eating their nutritionally balanced feed instead of snacks. Also clutter is a long term solution and can be rearranged to provide birds with something "new" to explore.