What are these?

My dad picked up a couple of boxes labeled "beekeeping" for me at a yard sale.

One had some old used frames that I'm going to burn, but another had a ton of these (flat), and a bunch of sheets of foundation.

http://imgur.com/3shvbsv

Any thoughts? The wood seems like balsa. Something soft. The flat pieces fold into the squares with slots in three of the sides. I'm not used to seeing square frames, so... shrug. The foundation sheets are deep-sized, rectangular.

Thanks!