Forest environment of red wood ant (Formica aquilonia) just after a rain. (note water puddle at bottom center of photo). The Norway spruce forest in Värmland, Sweden, is a rather wet place most of the time.
It may rain or drizzle almost constantly for up to two weeks. Usually there are a few days of no rain although it may be
still overcast. Sun my come out for an hour or two. Other times it may be dry and sunny for a week or slightly more. In any case, the snow melts in late April and then rain continues
periodically so that the forests are soggy with many mosses. I was told that Swedish lore has it that red wood ants ("röd skogsmyra" or "stackmyra" in Swedish) tunnel up to 2 meters below the surface of their nest
in order to avoid the freezing
winter temperatures and possibly for more room. However, I dug some holes around several ant nests in the photo to left and found that water seeped into the holes almost immediately
so that it would be impossible for any ants to build rooms below about 10 to 20 cm under the ground surface. I also excavated an abandoned nest and could not find any
evidence of tunnels below about 10 cm under the ground surface whereas the nest above the ground was riddled with tunnels and rooms (enlarged tunnels).
Images © 1996 by John A. Byers, Chemical Ecology.