because it's there
Last night, Jack found a little silver ball on the floor that had escaped when we made some decorations on Monday. See Exhibit A:
After a few moments, he pointed to his face and said "Ball! Nose!" and upon closer inspection, I saw a little silver glint in his right nostril. For reasons only known to his toddler mind, he decided to shove the decoration up his nose. Paul held his head while I tried to remove the ball from his nose with a pair of tweezers like a life-sized game of "Operation". It finally dropped out on its own and Jack went off on his merry way.
Seriously, why do kids do stuff like that? Is it to give us heart attacks?