I live in 3393 Dissent. When I checked back to my home, I have ONE butterfly. Before, I had as many as possible before the butterflies feel too crowded. What do I do now? Those butterflies are expensive.
Now you mention it, I noticed some milks on the ground once in a while. That stinks. It's the most expensive of all farm animals. Do you know how long they live?
Butterflies waft off to lepidopteral heaven after giving up a particular quantity of milk, rather than living a fixed amount of time; so if you have milkers in your home, those'll reduce their lifespans.
If you find caterpillars expensive, I'd suggest making your own - the raw ingredients for butterfly eggs are relatively cheap, after all.