Do chickens need light in the coop during winter?

As the days grow shorter and winter settles in, many chicken keepers start to wonder: do my hens need extra light in the coop to keep laying eggs?

It’s true that chickens are sensitive to day length. When daylight drops below about 14 hours, egg production slows and sometimes stops altogether.

That’s why commercial farms, and some backyard keepers, add light in the dark months.

But is it necessary? And if you do add it, what’s the safest way?

Why have extra light in the chicken coop?

As the days shorten, egg production naturally slows down. Hens start laying more as daylight increases in spring, reaching peak production when daylight hits around 16 hours a day⁽¹⁾.

That's nature's way of ensuring chicks hatch in warmer, safer months.

When daylight drops below 14 hours, the hormone flow that triggers egg laying slows too, and many hens stop laying altogether.

Commercial egg producers, and some backyard chicken keepers, add artificial light during the winter to keep hens laying for longer. The extra hours of light can trick a hen's body into continuing her normal laying cycle, even when it's dark outside.

For families who rely on a steady egg supply, or keepers who sell surplus eggs, extra light in the coop can make a big difference.

The biology: how light affects chickens.

Chickens process light differently than we do. They don’t just "see" it with their eyes: a thin patch of skull above the eye allows light to reach the pituitary gland, which then signals the ovary to start producing eggs.

The key takeaway is about timing:

• 14 – 16 hours of daylight is the sweet spot. Hens will usually lay an egg a day during this window.
• Less than 14 hours: hormones aren’t triggered strongly enough, and laying slows or stops.
• More than 17 hours: multiple studies show production actually drops again^(e.g. 2). So more is not better.

That’s why the length, consistency, and type of light all matter when deciding whether to add supplemental light in the coop.

Does adding extra light harm chickens?

This is one of the biggest concerns chicken keepers have – but the research is clear:

• Adult hens: there’s no evidence that supplemental light shortens a laying hen's life. She is born with all the eggs she’ll ever produce. Light just affects when she lays them.

• Young hens: this is where research shows caution is needed. Giving light too early (before a hen reaches 16 – 20 weeks) can trigger egg production before the body is fully ready, leading to health problems⁽⁵⁾.

• So the rule of thumb is simple: never add light until your hens are at least 16 weeks old – preferably over 20 weeks. 

Does the type of light matter?

Yes. Studies show that both the intensity and the colour of light can make a difference^{(e.g. 2, 3, 4)}.

Does extra light affect the quality of eggs?

No. Research⁽⁴⁾ shows that while extra light may increase the number of eggs, it doesn't affect shell strength, yolk quality, or nutritional content.

The only indirect effect comes from winter conditions: with less chance to forage, hens may miss out on bugs and greens that naturally enrich their diet. But that's a diet issue, not a light issue.

So, as long as you keep feed balanced and supplement with a few healthy treats, you can expect the same quality eggs whether you add light or not.

For tips on how feed influences egg quality, take a look at my guide to what hens should eat.

Pros and cons of adding light in the coop.

Pros.

• More eggs through the year: there's no doubt that adding artificial light to the coop during winter months can stimulate egg production. 

• Calmer, more sociable hens: studies^{(e.g. 2)} show that 16 hours of light can reduce stress behaviours like fighting and feather pecking in confined winter flocks.

Cons.

• Fire risk: unsafe wiring or an exposed light bulb in a chicken coop can, and frequently does, lead to fire.

• Physical problems: for hens younger than 16 weeks supplemental light can cause their bodies to mature too early. 

• Behavioural problems: too much light, or the wrong intensity, can spark aggression. 

• Needs consistency: if a timer fails or you forget to turn lights on or off, hens can become stressed and even go into a moult.

• Extra cost: the cost of keeping lights on may be small but should be factored in.

How to light the coop: dos and don'ts.

If you've weighed up the pros and cons and decided that extra light makes sense for your flock, here's how to do it safely and effectively.

Do...

• Add the light in the mornings. Work backwards from dawn to assess when the lights should go on and off. Allow for no more or less than between 14 and 16 hours.

• Use a timer for consistency. No need to dash out in the dark!

• Choose a diffused, soft white light that mimics daylight. The wattage will depend on the size of your coop. A safe option for small coops is a rope light like this one (affiliate link), fixed above the roosts, out of pecking range.

• Check your wiring and fittings are safe. Coop fires from faulty heat lamps and bulbs are sadly common.

• Reduce the hours of artificial light as spring brings longer days.

Don't...

• Ever use a heat lamp. It's something entirely different, not necessary for laying, and it's one of the main causes of fires in chicken coops. 

• Add light your coop in the evenings. Chickens need time to settle naturally as light fades gradually at dusk. A sudden blackout in the middle of the night will create anxiety and, potentially, injury.

• Forget consistency. If you suddenly withdraw the light, or forget to switch it on, or switch on and off at random, your hens are likely to go into a stress-induced moult.

• Start adding light when hens are less than 16 weeks old. Wait until they are 20 weeks or more.

Conclusion.

Whether or not you provide light in your chicken coop during the winter is a matter of personal choice. The evidence is that it doesn't physically harm your hens, and may actually help prevent damaging behaviours.

My personal choice is not to add light. Instead, I have a good number of hens I know to be excellent egg-layers for most of the year.

When they slow down or stop laying, I accept that as their time off work.

Whichever you choose, the key is understanding how light affects your hens and making the choice that's the right option for you, your family, and your chickens.

More about caring for chickens and eggs.

Sources and further reading.

A lot of "facts" you'll find on the internet are often people's individual views, often based on inaccurate information repeated from poor quality sources.

The information I provide in this article and others is based not just on my own experience, but on evidenced facts from scientific, peer-reviewed research and evidence from highly respected and experienced poultry keepers such as Gail Dammerow.

Some of the sources I have used for this article are these.

1. Bayram, A and Ozkan, S: Effects of a 16-hour light, 8-hour dark lighting schedule on behavioral traits and performance in male broiler chickens. Pub. Poultry Science Association, 2010.

2. Ostrander, C and Turner, C.N.: Effect of various intensities of light on egg production of single comb white Leghorn pullets. Pub. Journal of Poultry Science, 1962.

3. Alphin, R: Impact of light on poultry. Pub. University of Delaware, 

4. Jacome, I, et al: Influence of artificial lighting on the performance and egg quality of commercial layers: a review. Pub. Brazilian Journal of Poultry Science, 2014.

5. Er, D et al: Effect of monochromastic light on the egg quality of laying hens. Pub. Journal of Applied Poultry research, 2007.