My son only has to observe a behavior once, and if it resonates with him, he happily adopts it as one of his own.  Whenever he begins to exhibit a strange, and often disgusting, new behavior, I make it my mission to discover with whom it originated.  Licking inanimate objects–the bottom of his shoes, the fence at school, and his toys–was traced to a brand new student in his preschool class. I was especially surprised when I found Matthew peeing in our backyard.  I admonished him and took Matt to the bathroom.  Despite my best efforts, the behavior continued, culminating in an embarrassing incident where he attempted to pee in a trash can at school.  That teacher received one heck of a gift for Teacher Appreciation Day that year.  I confided my troubles to my older sister who sheepishly confessed to letting Matt pee off the deck of her house into the bushes.