We found a nest of tent caterpillars and I just had to show Brayden these little guys. After a few minutes of studying them and seeing that they didn't hurt me, he was ready to enjoy the feel of a caterpillar crawling up his arm.
Brayden took to tadpole collecting like a duck to water. We had a blast collecting these tadpoles and putting them in the aquarium I have set up on my back porch. Now Brayden can keep up with how much they have grown each visit he makes.