Vaseline. Seems to live in every bathroom cupboard in the land. I don't know what it's for, but I use it to catch Varroa mites in a sticky board test. Varroa destructor is a parasitic mite that attacks honey bees. The idea of the test is that some of the mites fall off their hosts, through the mesh floor of the hive, beneath which is a white board smeared with vaseline. The mites get stuck in the goo and you get a rough idea of the mite population in the hive. Fortunately in our hive, we have very few of the little gits.