Robert's favourite thing to teethe on is a tampon! Yup, my stash has depleted. Not good in an emergency for mumma but a quick dash to the shops (thanks DH) fixed that. He raids my drawer in the bathroom. First he empties them onto the floor and plays with the box (the little flick thing has him fascinated) and then he pops one in his mouth to chew. Guess they just fit perfectly in his mouth! I've found warped ones all over the house (toy box, car seat, pram).