This is one of our most popular beetle traps. That's because they're both cheap and convenient. Simply fill the trap with canola/sunflower/vegetable oil (the trap will hold approximately 25mL) or diatomaceous earth and drop it in between the frames. These beetle traps are deeper than other traps with a thin profile that makes it easy to slot them in between the frames. The transparent plastic makes it easy to see if they're full, and when the're full you can simply chuck the trap away and put a new one in.