Eastern Black Swallowtail Caterpillars

I found some little caterpillars on the fennel plant in the garden which was perfect because I was trying to attract them. I decided to bring them in and watch them grow. The birds are probably not happy about that :-(  Anyway, they're growing, as you can see! I hope to see them through their metamorphosis into butterflies. I'll happily release them when the time comes!