Maybe it's one of those mosquitos, that's a terrible device. They make a high Piitched noise only Teens and kids can hear, shop owners use these to scare away teens Who hang out in their shop. It works cause after some minutes the teens usually just go away cause they don't like the noise. It's very awful because also babies and animals can hear it. Imagine your Parents talking having a little baby with them in a store and that mosquito Starts to play.. What can the baby do about it but cry? :-/ and the Parents don't know why