Since this hasn't been started for 2017 I'll be the first.
I saw a few tiny little caterpillars on some potted milkweed a few days ago. Yesterday I looked again and didn't find anything except a few nibbled spots on the leaves. So today I looked again with scissors and a container in hand. I found several nibbled spots and only about 10 very tiny caterpillars. I saw several eggs and a female butterfly flitting about the milkweed patch. I found 2 large caterpillars on a plant in the back yard.
The large caterpillars are now in the butterfly habitat and the tiny ones are in a plastic mayo jar. I don't dare put the tiny ones in with the large ones because large caterpillars will eat small ones if they happen to be on a leaf they are eating. Also the tiny ones are so small they would get lost and possibly be crushed in the habitat.
I really hope I don't mess with the life cycle of the little ones too much if they are in a shady area outside. In a couple days they should be large enough to live in the other habitat.
The wasps and spiders have been taking more that their share of this years caterpillars of all species. I had a Giant Swallowtail laying eggs on my citrus trees and haven't found any caterpillars. And a couple days ago I saw a crab spider feeding on a caterpillar that was 3 times larger than itself. Yesterday I saw an assassin bug nymph on one milkweed plant.
Now I am drinking a bottle of ginger pop so I have a bottle in which to put a cut milkweed stalk in. I'll need another for the second habitat.