Bedbugs and Bean Leaves...

A long-established home remedy for bedbugs is to spread bean leaves around.  The bedbugs collect on the bean leaves and get stuck.  Then you just throw the bean leaves away, or burn them. 

Scientists have known about this home remedy for a long time.  Unlike many such remedies, this one actually works, and is well-documented.  Annoyingly, scientists couldn't figure out why it worked, and therefore could not devise an technology to make use of the same technique – any time of year, any where they had bedbugs.

Now they've figured out why, and the story is fascinating.  See here and here for details and photos.  Bean leaves are using the same technique that pikemen used to attack armored knights: aim for the greaves!