The Mystery Beneath the Leaves
Beneath the fallen leaves, a hidden world stirs. Insects, spiders, salamanders, fungi, and other small creatures slip into the shadows, finding shelter in the forest’s secret winter hideaway.
The fallen leaves and other woody debris that accumulate on the ground are a natural part of Michigan forests and make up what is called leaf litter.
Leaf litter is full of life. It provides shelter and food for bacteria, fungi, and tiny invertebrates, nesting material for birds and squirrels, hiding places for small woodland mice and salamanders, and protected spots for seeds to escape the notice of hungry birds.
Earthworms, snails, and millipedes feed on leaf litter, breaking it up into smaller pieces and making it easier for bacteria and fungi to decompose the tiny litter pieces into soluble chemicals and minerals, which are then recycled as food for the trees and other plants growing in the woods. Leaf litter also keeps the soil moist so new plant seedlings can grow.
As the weather turns cold, tiny firefly larvae burrow into the soil and rest under the leaves. Mourning Cloak butterflies spend the winter in a hibernation-like state within piles of fallen leaves. Luna Moth caterpillars wrap themselves in leaves that drop to the ground in the fall and remain there throughout the winter. Woolly Bear caterpillars tuck themselves into the leaves in a dormant state to wait for spring. Ladybugs gather in dry leaf clusters. Beetles use the rotting layers for both cover and food. Ticks hide in damp leaf piles to stay safe from icy winter weather. Bumble bees die off in autumn except for the queen, who spends the winter just below the surface of the soil under the blanket of leaves.
Small amphibians like the blue-spotted salamander burrow under damp leaves to keep from freezing. American toads hide in leaf cover during cold days and help break down plant matter. Ringneck snakes and other small snakes hunker down in leaf piles for warmth. Mice and voles tunnel through thick leaf piles to stay warm and search for hidden insects to eat. Spiders use the leaf litter as a quiet place to live and wait for prey.