Hello, thank you for sharing your feedback and we're disappointed to learn about the experience. It will be helpful to know that to set the trap, first hold the base of the trap in a horizontal position, and twist the top cover in a clockwise rotation (in direction of the arrow) until it locks. A red indicator will show through the hole marked "Set" on the top of the trap. A mouse entryway will open in front. We hope this helps! As the manufacturer of d-CON, we'd like an opportunity to assist you better. Please call 800-228-4722 between 9:00-5:00 EST (Monday - Friday) or send an email to us at consumercare_usa@reckitt.com, including the following case number RB0001667937, and we would be more than happy to assist. We look forward to hearing from you soon! Sincerely, Your d-CON Team!