Why Dryer Lint Is Dangerous for Birds

Wikipedia explains lint as: "Lint is the common name for visible accumulations of textile fibers and other materials, usually found on and around clothing. Usually found in the lint trap of electric clothes dryers. Certain materials used in the manufacture of clothing, such as cotton, linen, and wool, contain numerous, very short fibers bundled together. During the course of normal wear, these fibers may either detach or be jostled out of the weave of which they are part. This is the reason that heavily used articles like shirts and towels become thin over time, and why these particles collect in the lint screen of a clothes dryer. Because of their low surface area, static cling causes fibers that have detached from an article of clothing to continue to stick to one another and to that article or other surfaces with which they come in contact. Other small fibers or particles also accumulate with these clothing fibers, including human and animal hair and skin cells, plant fibers, and pollen, dust, and microorganisms.

The etymology of the modern word "lint" is related to "linting", the term used for the cultivation of the shorter fibers from the cotton plant (Gossypium), also called "lint", from which lower-quality cotton products are manufactured. Lint is composed of threads of all colors, which blend hues and may appear to be a uniform gray". (from Wikipedia)

There are many valid reasons why lint from your clothes dryer is inappropriate and can even be dangerous as bird nesting material, including:

Texture: Lint is broken down fibers and has zero structure of its own. Thus, it easily falls apart and is not robust nesting material to hold up to the actions of growing nestlings. When wet lint dries, it can become brittle and a hummer nest made of dryer lint can disintegrate.

Chemicals: Commercial/consumer detergents, fabric softeners and dryer sheets contain perfumes, soap residue and artificial dyes that ultimately end up in dryer lint. Large concentrations of these chemicals in lint can make it particularly toxic to the tiny animals.

Smell: Most birds do not have a significant sense of smell and may not mind the odor, those same aromas may attract predators to an exposed nest.

Residue: Small particles of dry, loose lint are easy to disturb can be airborne in the next and can be inhaled by birds, even young chicks. This dust can cause respiratory distress and even choking or suffocation in severe cases.

Mildew: When dryer lint gets wet it takes longer for the moisture to dry than more natural materials. A damp and moist nest may chill the baby birds, but the damp lint can develop toxic mold or mildew.

Tackiness: Wet dryer lint pulls apart easily but can stick to the nest surfaces and can become caked on birds' legs, feet and feathers.

Configuration: Dryer lint is made up of very small, fuzzy particles, however, longer threads of human and/or animal (cats and dogs) hairs can also be part of a mass of lint. Those long pieces combined with lint can tangle around hummingbirds' legs, wings or other body parts, potentially causing injuries similar to the effects of ‘being tied up’.

Since dryer lint presents so many negative characteristics for nesting hummer birds and chicks, it is not suggested to offer it as nesting material, even in small quantities.