This clear plastic queen catcher is for catching and holding a queen. If you need to transfer her to a queen cage or to another colony, this tool will help. It helps you handle her safely, and minimizes the stress that clumsy finger can cause. We have tested this tool out, and find it works well. Essentially, you open up the catcher and scoop up the queen with some workers. We were pleasantly surprised that the workers cannot get get through the cage. If you are transferring the queen to another hive, this reduces the risk of hostile workers attacking her while she is in the cage.