Carpenter bees are initially attracted to the trap by sight, when they get near the trap they smell the attractant that has been pre-treated in the trap. The bee goes inside and then can’t figure out how to get out! This carpenter bee trap is designed to hang where the bees are swarming. It is for people who have a bunch of plastic water (or soda) bottles around. Once the bottle fills up with bees just remove it and put a new bottle up! Almost any plastic bottle will work. Bottles are not included with the trap.