Adding Nesting Material to Birdhouses

Providing nesting material in birdhouses is an important part of attracting birds and encouraging them to raise their young. The right materials can make a birdhouse much more appealing to specific species. As experts in birding and avian conservation, we recommend using natural, biodegradable materials that mimic what birds would find in nature. In this comprehensive guide, we will discuss the benefits of adding nesting materials, recommend materials to use for different species, and provide tips on sourcing, preparing, and maintaining these materials.

Why Add Nesting Material?

Adding nesting material to a birdhouse provides multiple benefits:

Provides Comfort and Warmth

Lining a birdhouse with soft, insulating material helps regulate temperature and retain heat, keeping eggs and hatchlings warm. Birds innately prefer nesting spots filled with cozy material rather than empty wooden boxes.

Mimics Natural Nests

In nature, birds build nests out of a variety of materials including grasses, moss, leaves, mud, and fur. Filling a birdhouse with similar natural materials helps create an attractive, familiar environment.

Absorbs Moisture

Natural nesting materials absorb excess moisture from rain, nesting birds, and bird droppings. This helps keep the nest dry and prevent mold or bacteria growth.

Provides Traction

Materials like pine needles allow nesting birds to grip the surface while entering the box, turning their eggs, and feeding hatchlings. Smooth, slippery floors are more difficult for birds to manage.

Reduces Noise

Soft nesting materials muffle sounds from outside the birdhouse. This allows parent birds to quietly communicate with their hatchlings.

Secures the Nest

Nesting materials provide a structure to anchor the nest, keeping it stable and in place, even as fully-grown hatchlings move about.

Gives Birds Building Satisfaction

Gathering and arranging nesting material is an instinctive, rewarding activity for birds. Providing materials for them to manipulate and build their nest can make a birdhouse more enticing.

As you can see, nesting substrates offer many advantages. Let’s look closer at which materials are best for different bird species.

Best Materials for Different Birds

The ideal nesting materials vary somewhat depending on which bird species you hope to attract. Here are the top natural materials to use for some common backyard birds:

Chickadees, Titmice, Nuthatches

  • Dry grasses
  • Dog or cat hair
  • Cocoa hulls or dried moss
  • Shredded coconut husks

These small songbirds craft sturdy nests to keep eggs and babies protected in tree cavities. They frequently line nests with soft fur or hair which helps insulate chicks.


  • Twigs
  • Dry leaves
  • Rootlets
  • Thistle down

Wrens build domed nests filled with thicker, sturdier materials to encase their egg chamber. They commonly incorporate twigs, leaves, fibers from roots and bark.

Bluebirds, Swallows, Chickadees

  • Pine needles
  • Wood shavings
  • Straw
  • Dry grass

These species favor dry grasses and pine needles which allow air circulation and help regulate temperature and moisture in their nests. Chickadees will also use finer materials like fur or moss.


  • Wood chips
  • Sawdust
  • Bark strips
  • Dry leaves

Woodpeckers need a deep nest cavity padded with wood shavings and chips to keep their eggs from rolling. Some line nests with soft leaves or moss.

Barn Owls

  • Wood shavings
  • Straw
  • Sheep wool
  • Pine needles

To cushion their nest on hard surfaces, barn owls use plant fibers, straw, wool, and other soft materials. These help incubate eggs and support young.

Wood Ducks

  • Wood shavings
  • Sawdust
  • Dry leaves
  • Twigs

Female wood ducks create a deep, sturdy nest lined with downy wood shavings which help insulate eggs. After hatching, wood chips help prevent ducklings from sliding down steep cavities.

This covers some of the best natural materials to use for common backyard birds. Avoid synthetic fabrics like batting, or artificial straw and grass, as birds may get tangled or injured. Always use biodegradable materials. Next, let’s look at where to source quality nest supplies.

Sourcing Natural Nesting Materials

The best nesting materials are natural substances you can collect yourself or purchase. Here are some recommendations for sourcing different materials:

Dry Grasses and Weeds

  • Collect dead, dried grasses and weeds from your lawn or fields. Cut longer strands down to 2-4 inches.
  • Purchase bags of dried grass sold as pet bedding, reptile substrate, or decorative material. Avoid dyed or artificial grass.
  • Search for dried ornamental grasses like millet, rye, and flax straw. Excellent for braiding and structural nests.

Pine, Cedar, Aspen Needles

  • Gather fallen pine, cedar, or aspen needles from beneath trees.
  • Buy bags of pine shavings for small pets. Ensure they are chemical and additive-free.

Hay and Straw

  • Straw (from grains like wheat) or hay (grasses) sold for gardening make great fillers.
  • Avoid mildewed bales. Shake out loose straw or cut hay into 3-6 inch pieces.

Leaves and Twigs

  • Collect dried leaves that have naturally fallen from trees.
  • Prune small twigs no wider than 1⁄4 inch from brush or trees. Cut into 3-6 inch pieces.


  • Harvest moss from damp, shaded areas. Rinse and squeeze thoroughly to remove excess moisture.
  • Buy bags of preserved reindeer moss or dried sphagnum moss from craft or pet supply stores.

Fur and Feathers

  • Collect loose pet fur (cats and dogs) and gently brush/pluck to gather soft down feathers (chickens, ducks).
  • Ask neighbors who groom pets – they often discard shed fur.

Wood Shavings

  • Purchase chemical-free aspen, pine, or cedar shavings meant for pet bedding. Avoid dusty sawdust.

When sourcing materials, focus on those that are organic, chemical-free, and low-dust. Now let’s go over preparing the materials.

Preparing and Maintaining Nesting Materials

To avoid issues like pests, mold, and mess, properly prepare and maintain nesting substances:

  • Store materials in paper bags or mesh sacks, not plastic. This allows air circulation.
  • If damp, spread out clumps of grass, straw, moss etc. to fully dry before use.
  • Discard or compost nests after baby birds fledge each season. Old materials can grow mold and bacteria.
  • Monitor for pests like mites; discard entire nest or freeze materials for 24 hours to kill bugs.
  • Wear a small particle mask and gloves when handling dusty materials like pine shavings, sawdust, and feathers.
  • Chop longer fibers like straw, grass, twigs, and pine needles to optimal lengths of 2-6 inches.
  • Use 1-2 inches of loose substrate at the bottom of the box, packing more at the back where nests will be built.
  • Before the nesting season, refill houses with fresh, dry materials. Discard old, soiled substrates.

By sourcing clean, natural materials and properly preparing them, you can create an attractive, inviting environment for nesting birds. Now let’s go over when to add materials.

When to Add Nesting Materials

Aim to prepare birdhouses with fresh nesting materials just before breeding season when birds are seeking ideal nesting spots.

Early Spring Preparation

  • In most regions, add materials in March/April, before birds start scouting locations.
  • Adding early allows rain to settle dust before birds inspect houses.

Late Summer Refresh

  • After fledglings leave the nest, do a full clean out and add new substrates in August/September.
  • This prepares the house for fall/winter roosting birds seeking shelter.


  • Always add fresh nesting material immediately after cleaning out old nests and dropping.

An empty, cleaned box is uninviting to birds. Refill right away to make it welcoming.

Pre-Nest Building

  • Some birds may remove or ignore the substrates you add in order to build their own nest.
  • Put out a variety of materials and let them choose what to use for their architecture.

By offering an abundance of preferred, natural materials before and during nesting seasons, you can make your birdhouses as enticing as possible to backyard birds seeking a home.

FAQs About Nesting Materials

How much material should I put in the birdhouse?

Aim for 1-2 inches of loose material like grasses, pine needles, or wood shavings at the bottom. Pack 2-4 inches of bulkier supplies like straw, leaves, or twigs towards the back where nests will be built.

How often should I change out the materials?

Clean out nesting materials at least annually after baby birds fledge, or more often if the house gets waterlogged or shows signs of pests or mold.

Should materials fill the entire box or cavity?

No, the entrance hole and front half of the interior should stay clear for birds to easily enter and exit. Focus materials towards the back where nests will be anchored.

Can I use human-made materials like cotton balls or yarn?

Avoid synthetic materials, as birds can get tangled or injured. Stick to natural fibers like fur, wool, or down feathers for softness. Yarn also retains moisture.

What are signs old nesting material is unhealthy?

Look for foul odors, visible mold growth, large amounts of caked bird droppings, decomposing leaves or grass, and pests like mites, fleas, or lice.

How do I keep materials from blowing or falling out of the house?

Use a wire mesh cage or screen to cover the interior nesting compartment and prevent materials being removed by birds or wind gusts.

Will birds still use my box without added materials?

Birds have a strong instinct to build nests. But providing appropriate materials saves them effort and makes your box much more attractive as a nesting site.

Adding the right natural nesting materials to your birdhouses is an easy way to make the interior more tempting and suitable to breeding birds. Be sure to use appropriate materials for the species you hope to attract, and maintain fresh, clean substrates from season to season. Follow the recommendations in this guide, and the birds will thank you!


Providing nesting materials can greatly increase the appeal of installed birdhouses, making birds more likely to use them to raise broods. We recommend using natural, biodegradable materials that allow birds to craft secure, comfortable nests. Cater the supplies to favored materials of the target species in your region. Sourcing and preparing materials properly, and maintaining fresh substrates from season to season, will create an optimal nesting environment. An abundance of suitable materials saves birds effort while satisfying their natural nest-building instincts and needs. Any extra effort to fill your birdhouses will pay off with a greater chance of attracting nested pairs! We hope this guide gives helpful direction on choosing and adding the best nesting materials to your birdhouses.