OK so here is the storey. my 18 month old twins have become experts at removing every thing they have on, dipper included. they take off shirts wile running around the house. and when they are in there cribs for there naps they strip down everything then pee or poop on the floor. i have tried to duct tape diapers on but they just step out of them. How can i keep them in there diapers, when they are alone in there cribs? Is this a sign they are ready to be potty trained?