. >> reporter: it's a sound robert dahl hadn't heard before, a rude awakening around 12:30 this morningfirst parts of tree branching dropping on his group, then-- >> extremely loud and high- pitched, very high, shrieky scream. it was scary. >> reporter: dahl didn't know what to do, but screamed back, hoping to square it away. his cocker spaniel was petrified. >> our dog wouldn't even leave the bed at all. she was just scared to death. >> reporter: it wasn't until 8:30 this morning, dahl came across this. a baby fawn he's certain was pounced on and eaten by a mountain lion, nestled in the large oak tree the night before. >> there's been a lot of fawns and deer around. probably just waiting, waiting as part of the wild right there. >> reporter: he knows deer frequent his front yard in the middle of the night. >> that's deer droppings. >> reporter: the animals likely coming from the san mateo creek behind his house. >> probably just followed the water and the creek looking for food. >> reporter: greg brush lives across the street and heard the screeching sound, too. >> we have lots of kids