Horses, ponies, and lap dogs are pretty much common place as pets and I figured the Smaug, the Balrog, and the Watcher were far too large to fit into any jar and they would undoubtably take umbarage with anyone who tried. So I chose the neekerbreekers, (Sam's name for the midges of the Midgewater Marsh for the noise the make) but not for their appetite for hobbit. I chose them because they were small enough to put in a jar with a mosquito net lid for my protection, like I used to do with frogs, bees, and garter snakesback when I was knee-high-to-a-grasshopper.
Anyway, that's my story and I'm sticking with it.
'Share and enjoy'