Are the marbles with the socks?

We seem to lose marbles in this house very fast. We have four marble runs here that all came with marbles, yet we can't find more than a few at any given time. And if we do find one, it fits in one run, but not another. The upstairs run has small light- weight marbles. The new run downstairs has small regular-weight marbles. The one on the fridge uses normal marbles. It's all very complex and frustrating to poor Parker. I think when we move or our fridge breaks we are going to find thousands of marbles.