Incubating Duck Eggs Using a Homemade Incubator

Are you thinking of hatching your own ducklings using a homemade incubator? Need some advice on what to do, and what not to do, to ensure successful hatches?

My husband and I decided we wanted to add ducks to our family. We don’t have acres of land but, after some research I decided Indian Runner ducks would do well. They are small, they lay lots of eggs and they eat all the bugs that I don’t want in the garden. Don’t forget the free fertilizer!


While looking up incubators, I quickly learned they were really expensive for a couple ducks. I’ve heard some horror stories about the cheap ones. The next best thing was a DIY incubator. After several hours looking up different types of home made incubators. I thought a styrofoam cooler with a low wattage light bulb would be simple and cheap to make. I also really like DIY projects.

Homemade Incubator

I struggled and struggled to get the humidity and temperature right. When I finally got it somewhat consistent I purchased 12 duck eggs from a nearby farm.

I put the incubator in our kitchen so I could constantly keep an eye on the levels. This was my first mistake. The first couple days were fine, the outside temperature wasn’t too hot. Once the temperature out side started rising, our kitchen temperature was also rising, causing the incubator temperature to rise as well.

It was easy enough to put a towel over the incubator when it got cold but when it got too hot I would have to open the lid a little. This would end up dropping the humidity.


At night the temperature would drop several degrees. This was especially difficult on days when it was hot all day. By the time I was ready for bed the incubator lid needed to be cracked open still or it would get too hot. But if I left it open all night the temperature would be too low when I woke up in the morning.

A couple times my husband fell asleep on the couch and when he woke up at 1 or 2am it was still wasn’t cool enough to close the lid. So when we woke up in the morning around 7am it was below 37C and a couple times almost down to 36C.

To solve this issue some people wire in a thermostat to control the heat rather than opening and closing the lid all the time. If I build one again I will for sure add in this step. It’s one less thing to worry about and you will have a better chance at a successful hatches.

Are Temperature and Humidity Fluctuations okay?

Yes, to an extent. Throughout incubation there is a small allowance in terms of temperature fluctuations. Lower temperatures are much better than too high. The ideal temperature is 37.5C (99.5 f). If it is only short periods where the temperature is off by a degree or two, it won’t affect the internal temperature of the egg.

It’s similar to a human in the sense that we could have a cold breeze blow by and our skin may cool down briefly, but our internal body temperature doesn’t change. If we were to stay in a cooler temperature for a long period of time our internal body temperature would start to go down. However if we were to be in a temperature too high, even for shorter amounts of time we could get burnt.

Humidity can fluctuate as well but during lockdown and hatching it is important to keep the humidity up high. If the humidity drops during hatching it can cause the duckling to get shrink wrapped.

My Second Mistake

My ducklings were late to hatch. The first one internally piped on day 30 and hatched out on day 32. Because they were so late I had opened the incubator to candle them and thus dropping humidity. After the duckling had externally piped (in two different spots) I waited over 24 hrs before I opened the incubator again, but by this time the second duckling was externally piping. The duckling needed help so I had no choice but to open the incubator.

I quickly ran a small cloth under hot water and switched it with the one I already had in the incubator before taking out the first egg. This gave a sudden rise in humidity, and temperature, which helped balance out the heat and moisture lost when I opened the lid. But it wasn’t quite enough as they both had dry membranes and were beginning to shrink wrap.

Relative Humidity vs Humidity

Humidity is the amount of water vapour in the air regardless of temperature.

Relative humidity also measures the water vapour in the air at a given temperature.

I found this to be one of the most confusing parts of figuring out my incubator. Some websites say relative humidity and some just say humidity. From my understanding they are all referring to relative humidity. There is such a huge range from one site to the next.

Many people have successfully hatched duck eggs under a broody hen. And, since chickens don’t swim they are not adding the additional humidity that a mother duck would have.

Here is where I went wrong. I had bought a digital thermometer/ hygrometer but I also had a reptile thermometer/ hygrometer (non-digital). The temperatures read the same but the humidity was way off. The digital read 45% but the non-digital was reading 60%.

I assumed the non-digital one was correct because, looking at other people’s homemade incubators they only had a small cup of water to keep the humidity where it should be. I had 2 mason jars and a wet sponge to get my humidity up. When the ducklings were hatching and I added a wet cloth into the incubator. The digital one still only read 55% but the non-digital was around 75%.

It wasn’t until after they were hatching that I came across the article on how to check your hygrometers. Turns out my digital one was 10% under and the reptile one was over by 10%. So although I did successfully hatch 2 of the 3, had I checked the hygrometers before incubating, and thus adding more humidity, the hatches may have gone easier.

What Happens When They Get Shrink wrapped

It all depends on how badly the duckling is shrink wrapped. If its quite badly shrink wrapped it will need a lot of help hatching. If it’s only a little then it may only require a little assistance and be able to finish on its own.

For more details on assisting a duckling (or chick) with their hatch check out the post Should You Help a Duckling Hatch

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