You know those dog whistles that can only be heard by our four legged friends? Well there is also a pitch that only teens and those under 25 can hear, but this case the mosquito-like sound acts as a repellent to keep youth away. Check it out - can you hear it?
Right now it’s mostly used in shopping malls and stores to stem delinquent chilling, but could be put to good use in keeping unwanted priers out of your dorm room, booze burglars out of your alcohol cabinet, or for determining whether or not that new person you’re dating really is as young as they say.
