We use these rescue traps and there are two flavors of traps for the Rescue:

1. A water trap that uses an attractant and then a vial that you put into water.
2. Then below another vial where you can buy a 10 week supply that is $5 from Amazon. Or a 2 week supply where you soak a cotton ball.

It's pretty confusing, but just using the bottom one seems to work pretty well.