The candy wrappers by the shed were the first clue. Our suspicions were confirmed later when we heard squeals and giggles and the bark of a dog. I caught a glimpse of them once. We have some little girls living behind us now and they cut through our yard to get to their friends' houses.
I wish they would have asked us. It's not that I feel violated. It's not that I mind their trespassing. It's more that I would like to meet them. And, also, I would like to assure them that they are welcome to walk through our yard.
Maybe they aren't concerned about trespassing. Kids are different from how we were so many years ago. But I can also imagine that their squeals and giggles would be even more joyful for them if they knew that we delight each time we hear them. That is an advantage of asking.