Cotton Balls or Cotton Batting: While soft, cotton can absorb moisture, leading to mold and bacterial growth in the nest. It’s unsafe for delicate hummingbird chicks.
Human Hair: Hair is too thin and can entangle tiny birds, causing injuries or restricting their movement within the nest.
Yarn or String: These materials can fray into long strands that may tangle around the birds, causing harm or even death.
Dryer Lint: Though seemingly soft, dryer lint is fragile, falls apart easily, and may contain harmful chemicals or residues from detergents.
Synthetic Fibers: Materials like polyester or nylon do not provide proper insulation and can retain water, making nests uncomfortable and unsafe.
Feathers from Unverified Sources: Feathers can carry diseases or parasites, posing a threat to the health of hummingbirds and their chicks.
Treated Moss or Grass: Moss or grass treated with pesticides or chemicals is toxic and can harm hummingbirds during nesting.