I'll give Miss Cellania the benefit of the doubt and assume it's just a typo in this case, but I've noticed more and more lately that people seem, very strangely, to have trouble pluralizing words that end in -ist.
As long as it's properly engineered and constructed, it would be no less safe than a balcony, which technically I guess it is. I'd be more worried about what the baby might rain down on passersby.
As opposed to any other kittens?
But I sure as hell hope he's feeding it more than sugar water. Hummingbirds need bugs, too.
"Scientists."
Or for those who aren't idiots, SAWDUST.