in my last colony i often-times build a bunch of graves like a 4x4 field (without space between them, i think that they will be able to walk over them) but my people keep glitching out to put them into the grave (they just shake them with themself irratically). it almost looks like they make forceful love with them^^, this was especially funny as i used the corpses for meat and after he made that "dance" with the corpse he butchered and ate it x'D.
fyi: don't butcher corpses, colonists seem to be picky about their meat (am newby, somebody should've told me).
to bump this and give it more understanding, here is the example:
http://youtu.be/E6BPkiCBilE?t=5s