The SERC science fair project: frozen worms. We freeze our compost to make sure any worms or eggs that we could not remove do not introduce the non-native red wigglers into the Mid-Atlantic environment. This winter we maintained an indoor bin and 2 outdoor bins. The outdoor bins appeared to freeze solid in the harsh conditions this winter, but the worms were hale and hardy when mild temperature returned. We wondered if worms could survive freezing (not so good for our method of avoiding introduction) or if they were protected from freezing by the insulating qualities of the compost. Our results did not support either hypotheses. The control worms in a tub but in the compost bin were lively, but those in the 2 freezer tubs were dead. Both frozen groups demonstrated some defense mechanisms. Those frozen in the tub with no compost were huddled together in a wormsicle conglomerate. Those that had been covered with compost were eventually located, after a couple hours of thawing, massed in the center of the compost. They appear to have crawled as deep as possible and massed together before they succumbed to freezing. We discovered after our experiment that our freezer was 12 F, which is significantly colder than the 24 hour average temperature this winter. It is also possible that a larger mass of compost and a larger population of worms for huddling provide more effective insulation from extreme temperatures. The kids think the worms, which are cold-blooded, animals might use a similar huddling adaptation as Emperor Penguins, warm-blooded animals.
