This is what happens every time around 4:00 in the afternoon (sometimes sooner). Keesje and Ed will put their front paws on the edge of the pen, squeal like crazy and Keesje will try to sink her teeth into the broomhandle.

It gives a very distinct rattle that I've long since learned to ignore, they only get their food at 4:00! Ed doesn't share the gnawing threat Keesje has, thankfully.