The bats multiply by themselves every two seconds, but you can click on them to make them multiply. Without clicking them, you can only get 3 bats at a time. When they multiply, they change colors. They disappear every two seconds as well, so see how large you can make your colony! If you click the star in the bottom left corner, all the bats disappear except one. Click that one to make new bats! Note: It gets out of control pretty fast!
This is just an experiment with clones.