This is the same little milkweed plant that had all the monarch caterpillars on it this past summer. After the caterpillars grew up, I trimmed the plant back. The new growth that followed was taken over by mites. I sprayed with insecticidal soap, which worked a little, but not too well. But the mites were soon replaced by the yellow aphids. I left well-enough alone, and today, I realized that my little milkweed plant was now covered with baby monarch caterpillars once again. And waaaay to many for such a small plant.
Anyway, I knew there were waaay too many caterpillars for one little plant to support, so I picked off as many as I could find, and took them to the arboretum, where I spread them among the many available milkweed plants. There are 32 visible in this photo, but after I returned from releasing them, I found 5 more still on the plant that I had missed. I will leave them there. But can you imagine over 3 dozen caterpillars on a single milkweed plant!