I tend to leave it on DS (can't remember when he started wearing his) and I had to take it off when he was in the baby room at CC - they were worried about it; if I didn't take it off they would during the day. Now DS's in the toddler room it stays on (except for swimming and bath time). Mind you we're on our 3rd necklace - the first one broke at CC in the baby room even though it was individually knotted I think I lost a couple and the second one has a magnetic clasp - DS kept pulling it off. Th current one is one amber bead short now near the clasp as DS decided to chew on it while we were in driving around Qld last holidays - thought he was going to sleep but no he was chewing away at his beads . Now we keep more of an eye out for that (have a baby rear view mirror in our cars - didn't in the hire car we had) and remove it from his mouth when he starts that now. I think he was also bored at the time as we'd been in the car driving a lot