Dryer Lint for Bird Nests

Get rid of it. It is highly flammable. Not true that it is only from the dryer. You don't see the lint that goes out the washer water.

In the old days washers had filters you had to clean and there was a lot more lint there than from dryers. Put it in the trash.

How Dryer Lint Is Dangerous for Birds
There are many reasons why dryer lint is inappropriate and can even be dangerous as nesting material, including

Texture: Lint is stripped fibers and has no structure of its own. Because of this, it falls apart easily and will not hold up to the actions of growing nestlings. After wet lint dries, it can be particularly brittle and a nest made of dryer lint will disintegrate.
Chemicals: Depending on the exact detergents, fabric softeners and dryer sheets used, lint can contain perfumes, soap residue and artificial dyes none of which are safe for birds. The higher concentration of these chemicals in lint can make it particularly toxic.

Scent: The fresh scent of warm, dried laundry can be wonderful for humans, and while most birds do not have a strong sense of smell and won't mind the odor, those same scents can attract predators right to a vulnerable nest.
Dust: The small particles of dry, loose lint are easy to disturb and can be inhaled by birds, even young chicks. This dust can cause respiratory distress and even choking or suffocation in severe cases.
Mold: When lint gets wet, it will retain the moisture for far longer than more natural materials. Not only can staying in a damp nest chill birds, but the wet lint can develop toxic mold or mildew.
Stickiness: Wet dryer lint pulls apart easily but will stick to many surfaces and can become caked on birds' legs, feet and plumage. In severe cases, this can disrupt the insulation of a bird's feathers and may have even more harmful effects on the development of feathers in altricial chicks.
Composition: While most dryer lint is made up of very small, fuzzy particles, longer threads or hairs can also be part of a mass of lint. Those long pieces can tangle around birds' legs, wings or other body parts, potentially causing injuries similar to the effects of fishing line.
With so many hazards that dryer lint poses to brooding birds and chicks, it is never a good idea to offer it as nesting material, even in small quantities.