I haven't hit one  YET!   I've come close a couple of times.   Our area has a herd or two that hang out in our fields.   If driving in the evenings  I slow down to 45mph on the blacktop road.    Our son lives in Kansas City area and we drive 36 to Macomb.   We leave early enough not to drive that road in the dark.    Does anyone else think that deer whistles work?    I 've  spotted many of deer stop in the ditch and wait, till I honk and send them one way or another.    Until we hit  a deer with deer whistles on our vehicle  I'll believe in them.