Use more than one at a time for better mischief. As long as you hide it well enough, no one can easily find it. You hide it: near beeping appliances, under desks and chairs, on the backs of potted plants, in air conditioner holes, near exhaust vents, near clutter, above chandeliers, and even in impossible places: like the backs of leaves. .The top of a car glove box, inside a mattress or sofa... It squeaks or bugs sound intermittently. It can make the prank victim wonder, lose control, and even scream. You can even set up a camera ahead of time to record what the other person is going crazy with. A battery is included in the package. This is really fun. The battery is valid for 5 to 6 years. The power can easily support it to run continuously for 6 to 7 days. Easy to use: Built-in multiple screams and multiple cricket calls. You can click a button to choose a sound. Each time it will play randomly for 1-10 seconds; [Mode 1] switch to S1, the interval is 3 minutes; S2: the interval is 3-10 minutes. Mode 2Long press the noise reduction button and toggle the switch to S1 or S2; S1: beep interval 10-20 minutes, S2: beep interval 15-30 minutes. (Note: closing will reset the PCB to default model) Small size and light weight: 1.5*1*0.4 inch and 0.2oz. Unconcerned corners of indoor places such as homes and offices will be its best hiding places. You can even use a small sticker to attach it to the back of the plant leaf . Run it and hide it: the sound of the interval makes him/her upset and can't help but want to find it. But I am very sorry. As long as it hides well enough. No one can find it. Before finding it, the people who are looking for it will growl and become furious.