Bats are flying enemies that appear in World 1 and 2 that can be stomped on and shot. Most bats hang upside down stationary against a wall or ceiling until the player reaches their level, at which point they will attack from above. While the bat is in its attack state, it acts identical to a Bad Bubble, except much faster with no speed buildup needed, no bouncing, and usually able to minimally pathfind. It is usually safest to kill bats before continuing downward, especially in Levitate Style whereas the player might jump right back into the bats they didn't pick off from before, due to their increased airtime. Bats can be lured in the same way Bad Bubbles can, by waiting for them to come to you, and then jumping.
When killed, Bats will drop 12 Gems.