This Week Outdoors: During periods of extreme cold, deep snow, heavily ice-crusted snow or combinations of all of these, squirrels will remain inside their den trees and nests most of the time.
Question. In a pile of old leaves and dirt in a corner of our raised deck, I found a couple dozen earthworms. The deck is made of the Trex plastic wood-substitute and is about eight feet off the ground. How did the worms get there? Alex Tierney, Harrisburg.
Answer. Those earthworms probably were brought up onto the deck and into that pile of litter as earthworm cocoons stuck to the legs or feet of a bird. They may also have arrived in an earthworm that was ready to deposit eggs but was interrupted and transported to the deck by a bird.
The earthworms most likely did not crawl up the supports of your deck in search of what turned out to be a comfortable and nurturing earthworm environment.
Cocoons are basically earthworm eggs. They are very soft when deposited into the soil, but quickly take on a tough leathery exterior.
Depending upon the species, the temperatures and the soil moisture, earthworms can take three weeks to five months to hatch and another three weeks to a year to grow to maturity.
Question. You showed a picture on PennLive of worms on a driveway in January. Why do they sometimes come to the surface in winter? Sally Heffner, Carlisle.
Answer. Many of the 30-60 species of earthworms found in the U.S. are of the type that commonly emerge when the earth is saturated with moisture. Those are the earthworms we commonly spot on our driveways on damp mornings and after rain has fallen.
They survive extreme conditions by tunneling down into the soil. Some of their tunnels can dive six feet or more straight down.
To avoid the freezing conditions of winter, they spend the season below the frost line. During the coldest, most frozen periods, they live in small chambers at the bottom of their tunnels. They secrete slimy mucus to coat the insides of the chambers, which helps them to maintain their critical internal moisture.
However, they are not hibernating and when temperatures above, in the soil and the air, climb, they move upward through the soil and may emerge aboveground. That can take place any time there is a sufficient period of warmer temperatures, even in the middle of winter.
Send your nature and wildlife questions to Marcus Schneck at firstname.lastname@example.org. You also can share your photos of wildlife and the outdoors with other readers by sending to schneck at the same email address.