We call nuts that were not removed at harvest "mummies". Our most destructive insect pest, the Navel Orange Worm (NOW), overwinters in the mummies as larvae. I refer to the mummies as "NOW Hotels" since the worms seem very happy in there waiting to become active again in the spring.  Because this is the NOW's only overwintering site in almond orchards, we can dramatically impact the NOW population by removing and destroying the mummies. The process of removing the mummies is referred to as winter sanitation.

There are two common methods of mummy removal. One method is "poling", in which a crew uses bamboo or fiberglass poles to hit the limbs and knock the mummies loose. The mummies are most easily removed if they are wet from rain or fog. Under dry conditions they can be difficult to remove.

The other method is to use a shaker machine, the same ones used at harvest. Shaking can be more economical than hand poling, especially if the trees are large or dense or there is a large number of mummies. Knocking cannot be used in some fields where because of wet conditions the machine will cause rutting or get stuck.