The culprit, correctly guessed by most, was this little guy:
Surprise, surprise.
The number of straws was.......10! And if you can look at this picture for longer than .5 seconds and still eat lunch, bravo to you.
Congratulations,
Emily and/or Eric, you correctly guessed the number and the culprit. Vanna, let's show them what they've won:

You will be the lucky recipients of 4 Coupons, each for a free Jr. Frosty from Wendy's (our family's favorite things to slurp with straws).
Thanks for playing everyone! And special thanks for those who voted for Peter or shared lovely stories of things found in their own pipes; you totally made my day.
BTW, when I was trying to come up with a one liner about how we know Emily + Eric, it was next to impossible to sum up briefly: Emily grew up next door to Peter, took piano lessons from the same beloved teacher as me (and we had many a group class and recital together), married Eric, who is my brother's wife's brother, lived in the apartment attached to Peter's parents' house after they were married, and Eric dated my sister in a galaxy long long ago. I'm sure there are other connections that I'm missing, but those are the main ones. That's the Cache Valley Cabal for you!