Marbles, Marbles everywhere

Cole has been especially interested in playing with marbles lately.  Obviously you wouldn't give marbles to someone young or a child who puts things in his mouth, but luckily I don't have that problem with him.  As he's playing with them he is learning. For instance, he hauls them around in his semi and likes to stop and start quickly and move the semi quickly to see how they roll and the noises they make.  He also likes to put them in his dump truck; however, since it doesn't have a tailgate the marbles wouldn't stay in.  So  1 row of duct tape on the back of the truck was added to hold the marbles in.  He discovered that most the marbles stayed in but if he was going fast he lost some, so a second row of duct tape was added - problem solved!  Other times the marbles are used in the play kitchen and they are discovering that different size containers hold different amounts.  Granted, at times I get tired of finding a marble here and there and sometimes they get dumped and are everywhere.  When I get tired of them they will disappear for awhile!