Or more specifically their train tracks. I have started babysitting for this family on the weekend that has 2 boys. Now Little Dan loves train tracks, and it's not just him. It is all (or all that I have known) of them. The last time I watched these two little boys, they wanted me to build a train track. And so I did. And here it is:
And they played with it all day!
Happy Munchkin Monday :)