My DD2 is nearly (sob) 2. She still does it on occasion. Especially with her favourites.....crayons in particular. She is my first out of three that have ever done it. She seems to revert when we are somewhere new, like last night at a friends new house for a BBQ and she had everyone in horrors.
That's just the way she explores.
She's pretty tough my youngest squirt. Gets sick much less than her two school aged siblings lol.