Herbal flea collars, though they don't contain the poisons that conventional flea collars do, come with the same warning: do not let children play with the collar. (learn.eartheasy.com)
They do, however, recommend that children should not play with the collars, and should be quarantined from the pet during the first day that they are wearing the collar to minimize exposure to the child. (wileypup.com)
To stop rough play with collars, we usually spray them with something unpleasant like Bitter Apple for a few days so the dogs get out of the habit. (dogfencediy.com)