How To Care For Your Nesting Box

In this post I am going to go through some of the best ways to maintain and protect a bird nesting box. I first thought about this when I started noticing how high on buildings some nesting boxes are. Given that so many are not easy to get to, I have been wondering – does a bird nesting box need to be cleaned? Should we be maintaining them and if so, how?

Quite simply, bird nesting boxes do need some attention from us. They should be cleaned out in the autumn, from September, after birds have finished using them. It is important to do this as any lice, fleas or parasites inside may infect the next family of birds using the box. There are other things we can do to maintain our nesting boxes to ensure they are used over and over. From treating or painting them to protecting them from predators. Let’s get into that now…

Should I Remove An Old Nest From A Bird Box?

The general advice is YES – you should give you nesting box a good clean out every year. However, whether to clean out a nesting box is up to you; it may or may not influence whether a bird chooses to use your box. There are studies that have been done around this and they have found that some species prefer to build on top of an old nest. Some prefer a clean space to start from scratch; a bug and parasite free environment for their young to hatch in to.

The same studies have also shown that certain species of bird, like the House Wren, will clean out old nesting material from a nesting box themselves.

Nesting On Top Of An Old Nest

Building a nest from scratch takes time and energy, both of which may be in short supply at a critical time. So if a bird does this, there is a danger that nesting on top of another nest will increase the proximity to the entrance hole. This will make it easier for potential predators to reach young birds inside. Another good reason to clean them.

In general, our garden birds will much prefer a nice clean nest box in which they can make their own nest. Let’s look at how to do that.

How To Clean Out A Nesting Box

Wherever you go on the internet the advice for cleaning a nest box is usually the same, if not very similar. One thing is for sure – nest box hygiene is important. By keeping a well maintained nesting box you will get results and birds will make use of it. Here is what you should do.

Take Down The Nesting Box

By removing the nesting box from its location will make it safer to work on. You don’t want to be up a ladder or leaning of a window while doing this, especially it will involve boiling water!

Remove The Contents

If you are lucky enough to have had nesting birds use your box there will be something in there to remove. Take out the old nest in one piece if you can. It can be disposed of on a compose heap or in a compost bin. If you have neither, the garden waste bin should be appropriate.

Don’t Breathe In

When you disturb the old nest dust and debris may be thrown into the air. Be careful not to breathe any of this in. Remember why we’re cleaning this box out? Parasites, lice, ticks, fleas… It is easy for humans to contract disease from wild birds by simply breathing the dust of dried bird poo and even from physical contact. See my other post here – Garden Bird Feeders Spread Disease : Fact or Fiction?

Dead Chicks & Unfertilised Eggs

Especially with boxes used by blue tits, there are likely to be a few unhatched eggs, or even some dead chicks. It can be sad but it is nature’s way. Make absolutely sure the nest is no longer in use before removing any unhatched eggs. There are laws in place to protect wild birds and their nests (Wildlife and Countryside Act 1981). *See footnote.

Use Boiling Water

Once your nest box is down at ground level, give it a good wash through with boiling water. You do not need to use any detergent or soap products; the purpose of using boiling water is to kill off any remaining parasites, bacteria and bugs. Do not use any pesticides or flea products – these can be harmful to birds. You can carefully give the inside surfaces a light scrub with a stiff brush to tackle any stubborn debris.

Roosting Material (optional)

Allow your nest box to fully dry before re-siting. Before you replace the nest box, it might be helpful to put some clean wood shavings or moss inside. This is not essential it but provides some bedding material for any bird who chooses to roost in your nest box.

When To Clean Out Bird Nest Boxes

The time of year to clean your nest box is from September onward. By this time the young birds should have fledged and the any nest inside will have been abandoned. Although September is the usual advice given, it may be worth waiting until early October to be absolutely sure the nest is finished with.

For example, the annual life cycle for a blue tit begins in February, when nest site selection starts. By the end of April the nest is built and by May the egg laying has begun. It is not until June and July that the young birds are ready to take flight.

This is a general overview of a blue tit’s year, from nesting to fledgling youngsters. However, some may be late to the game and won’t start until April or May. This could delay the end of the process until at least August, so approaching a nest box at the beginning of September could be premature.

Of course, if you have a nesting box with a camera, you will know when the time is right.

Using Paints And Stains On Nest Boxes

If you care about providing the best nesting box you can, you will have already bought a good quality one, or made one to a decent standard. The question is – do you really need to paint it? Painting a nest box can give it a nice look and, in some cases, make it more appealing to certain species of bird. Using a wood preservative might be a more sensible idea. Although, the only real benefit is to prolong the life of the wood.

Simple, Not Stylish

The RSBP advise us to “… Keep nest boxes simple, not stylish.” I agree that nest boxes should be more functional than stylish. After all, who benefits from a colourful and decorative nest box? Not the birds.

So, try to avoid painting your bird box bright colours and while children like to paint funky patterns on stuff, it may not suit a nesting box. If you want to paint your nest box choose natural, more subtle colours.

What Kind Of Paint Do You Use On A Birdhouse?

There are conflicting opinions on whether to paint a nesting box. Some sources say the best for a bird is something that closely resembles their natural environment, i.e. natural, untreated wood. The RSBP website, though makes reference to making a nest box then painting it to make it more personal.

There are two main things to consider when choosing a paint for nest boxes.

  1.  The colour you choose may look nice to us but may put off a bird looking for a nest site. Some darker colours retain the heat, while lighter colours, such as white, reflect the heat. Brightly painted nest boxes are known to have attracted predators. Instead, choose more subtle and natural colours that resemble a bird’s natural habitat – browns, greys and greens could be suitable.
  2. the base of the paint you use can have a negative impact on a bird’s health. Oil based paints give off toxic fumes and these fumes can persist for weeks, if not months. Water based paints are more suitable and becoming more popular than oil based paints around the house. Many water based paint products also perform better than oil based alternatives.

Bird Safe Wood Finishes

If you really want to paint your nest box, go ahead. There is nothing wrong with it but be mindful of the advice given about colour choice and the health risk of oil based paints.

A better option which is in keeping with the ‘simple, not stylish’ advice, given by the RSPB, is a stain or wood preservative. The main function of a preservative is to prolong the wood’s natural strength, shape and integrity. A preservative can provide protection against the year-round elements, keeping your nest box going for longer.

It is so important to use a bird safe stain or preservative. Again, water based preservative will be a better choice for a nest box. The oil based preservatives will continue to emit fumes for quite some time.

Protek is a leading manufacturer of quality wood stains and preservatives. They have been working with the RSPB ensuring all their products are bird safe. You can read the article here.

Using Nest Box Hole Protectors

Another thing you can do to care for your nesting box is to use nest box hole protectors. These are small plates, made of metal and usually square shaped. In the middle of the plate is a hole to match your nest box hole size. By attaching this, or other similar nest box restrictors, you provide two things.

  1. Firstly, they provide additional strength to the nest box entrance hole while preventing damage around the hole from constant use and pecking around by birds.
  2. Secondly, they protect a bird box from squirrels and other predators. By using a metal plate with a predefined hole size, the birds will be able to access the box but larger predatory birds and other garden predators like squirrels will be unable to access the box.

A nest box hole protector is easy to fit and will only take a few minutes. They are normally fixed with short screws, which you will need a screwdriver to insert.


Hopefully this post has given you some useful information. Putting up a nesting box for your garden birds can be fun and exciting. But, neglecting a nest box could mean the birds go elsewhere to find a better alternative.

It is only once a year that we need to clean out a nest box and it takes just minutes. Remember, this must be done at the right time of year when the birds have left the nest. Do it safely at ground level, rather than hanging off a ladder or out of a window.

Painting a nest box isn’t a big recommendation but if it something you want to do, choose a suitable water based, non-toxic paint. Also choose a natural colour, avoiding brightly coloured paint. Stains and preservatives are a better alternative to paint. Again, water based is best.


*In England and Wales, General Licence permits unsuccessful eggs to be removed from 1st September – 31st January. In Scotland, General Licence permits unsuccessful eggs to be removed from 1st August – 31st January.

It is illegal to keep any unhatched eggs. If there are unhatched eggs in the box, the relevant General License permits egg removal between 1st September and 31 January, and you must throw them away.

Quoted from the RSPB website.