Insect ID: Where did you find it?

Note for May 2021 (and probably May 2022 as well) for Maine: If you are finding hairy caterpillars by the hundreds or thousands in your oak, cherry, pear, apple and/or crabapple trees or maybe they are crawling all around on the sides of your house, garage, porch, etc. they are probably this dreaded critter: Browntail Caterpillars