Lack of proper supervision and you need to tell this to someone in charge if you can, well done ,for realising this should not be happeningthe above post is correct the Moms are paying for their children to be looked after properly this doesnt sound right, you wouldnt ask here for advise if you thought so take it a step further,
are you asking because you see this happen? it shouldn't be happening at all. of course toddlers to occasionally do those things, but it definitely should not be the norm. if it is occuring, it is probably due to inexperience or poor training of the staff. children who are kept busy and stimulated with developmentally appropriate activities would not consistently behave that way.