You can also catch them in insect nets or jars (which are the upcoming two new items). Caterpillars are also upcoming. Also I'm sorry I didn't post for a while. I was a little busy doing the Zoolocraft project. But unfortunately, Bridge V2's newest update removed the project off of my list. But at least the entity, item's, block's, and the eucalyptus biome's code is still intact! And I was still able to open them!
Vector art and butterflies made by me by using Scratch and Blockbench