How To Clean Out A Bird Nesting Box 

As humans, we often wonder whether we should do anything to help wildlife, or whether it is more interference than good.

In this article, we will explore the question of whether we should be cleaning out a bird nesting box, and if so, how and when we should be doing it.

Should I Clean Out my Bird Nesting Box?

Yes, it is a good idea to thoroughly clean out your bird nesting box once all the birds have flown the nest. The main reasons are that cleaning will prevent parasites from making it their home, and it will increase the chance of survival for the new family of birds that occupy it:

  • Parasite Prevention

One of the main reasons to clean out your birdbox is to get rid of any parasites that may be lurking inside. The wooden material of most nesting boxes can harbour parasites or their eggs, which is important to get rid of before the next nest is built. The presence of parasites in the bird nesting box will reduce the new birds’ chances of survival.

In addition to this, the box should be cleaned out because there could be dead birds or unhatched eggs inside. Leaving these in the box will increase the chances of parasites flourishing while the nest is unoccupied.

The prevalence of parasites in old nesting material is the reason that birds often choose a different nesting site each year, rather than returning to an old one.

  • A Build Up Of Material

Another good reason to clean out your bird nesting box is because some birds won’t do any cleaning themselves. This means that over time the nesting material will build up in the box, until the nest is perilously close to the entrance hole.

This means that the baby birds will be more visible to predators, and also may be more susceptible to falling out of the nest. Bluebirds are the most common example of birds that don’t remove any existing nesting material before they begin making a new one, so watch out for this if your birdhouse is housing them.

Re-Using Nesting Material

Cleaning out your bird nesting box is a great way to provide some shelter and nesting material for small mammals such as mice. You could even place the bird box on the ground as is, after removing any unhatched eggs. If your bird box is occupied by rodents over the winter, it will need another clean before it is occupied by birds in the spring.

If you want to use the box over the winter months for small mammals or even some birds roosting, then you can line it with a small number of dry leaves and wood shavings.

When to Clean Out Bird Nest Boxes

It is best practice to clean your bird nesting box in October or November, when you can be sure that the occupiers have flown the nest. This will mean that any parasites can be removed well in advance of new occupants.

It’s worth noting that in England, Wales and Northern Ireland, unhatched eggs can only legally be removed between September and January. In Scotland, unhatched eggs can be removed between August and January, but it is not advisable to clear out a nest in August since some birds may still be nesting.

When to clean out bird nest boxes in your garden will depend on the type of bird occupying them, and when they usually leave the nest.

How to Clean a Bird Nesting Box

  • Step One: Remove Nesting Materials

The first step to cleaning your birdbox is to take off the lid and remove the existing nesting material, along with any unhatched eggs and dead birds. As stated above, it is illegal to remove unhatched eggs at any time other than September to January, and the eggs must be disposed of once removed. It is illegal to keep and store any unhatched eggs, so make sure they are disposed of in the correct way once removed.

  • Step Two: Kill Parasites

Once all the nesting material has been removed, the next step is to kill any parasites in the box by pouring boiling water directly into it. Boiling water will also kill any parasite eggs, which ensures that the new occupants have the best chance of survival when they move back in.

Some mild disinfectants may be used, but do not use any flea treatments or insecticides in the box; these can be harmful to the new birds.

  • Step Three: Drying

After boiling water has been used to kill any parasites and their eggs, the bird box should be left to dry completely. It’s a good idea not to replace the lid until the box is fully dry. 

Preparing a Bird Nesting Box

When the time comes for the box to be reoccupied, you can help to attract birds and provide a foundation for them to build their nest on. Most birds do not require any existing materials when they are sourcing a nest site, so this step isn’t often necessary.

If you are preparing a bird nesting box for new birds then make sure you are educated on the types of materials to use, and which to avoid. Some plants can be poisonous to birds and so birds won’t nest there. Different birds will require different nesting materials.