I spy a monkey

We have a bunch of I Spy books that we got for Parker a couple of years ago and now read to the girls as well. In I Spy Little Letters, each page has 1 or 2 decorated letters, surrounded by doodads that start with the letters on that page. The A page has an airplane, an ant, and an astronaut, among other things, all surrounding the letter A.

When Parker was just learning to talk, he always like to point at the little monkey on the M page, and say Ooh Ooh Aah Aah. I don't remember if I taught or encouraged him to do this, but you could count on him doing it every time.

Last night I was reading this to the girls at bedtime, and was very surprised when we got to M to have them both start scratching their armpits and saying Ooh Ooh Aah Aah. I didn't teach them to do this, so there must be some sort of primal force at work here.