That kitten LOOKS innocent, but he doesn't fool me.
>> These kittens ,, would jump bite hold, and destroy the entire envelope ,, Rick
Got it. I didn't think about that.
>> I would have to hang those from the ceiling
Reminds me of Flanders, NJ, where I had a bird feeder hanging from a tree limb, over my head. One day I found it one ground, torn apart, with four BIG paired holes punching CLEANLY through tough, heavy-gauge plastic. Bears had been sighted in the neighborhood ... or maybe it was a relative of your kittens.
My cat is amazingly cooperative some of the time. But I would never put seeds on top of anything he feels he owns, or wants, or is curious about.