Not totally relevant but another thing to watch for most likely with your own children, if you pop outside for a second they may lock you out... I popped out front door to get a flyer on my front porch and my then 22 mnth old turned the deadbolt...I had water on stove coming to the boil for supper. . I sprinted to neighbour's holding my 8 mnth pregnant belly to call my husband home from work which was luckily 5 min away to come and open.