I've got an old incubator (Styrofoam) that I've been using on and off for years. I have decent success using it, I make sure to bleach it before I use it. It's the cheapest model you can use (still air), but it works. It's good if you have hens that won't set. Not sure which kind of hens you have, some won't set no matter what (like leghorns). The ones who set can be real pains about wanting to set as well. Sometimes I'll use old eggs as 'decoys' (I mark them with a big black X) or you can use fake eggs that some stores sell (like mcmurray hatchery) to entice hens to set, but it's up to the hen. I'm trying to get a blue laced Wyandotte to set, I've got about 8 eggs in her nest and I have the 'good eggs' (ones I want her to set on) waiting in some egg containers. If you try that, make sure to tip the egg containers on a slight incline a bit so that the egg yolk doesn't stick to the inside of the shell. I make sure to alternate which side is tipped up at least 3 times a day and try to keep them in a cool place. I'm getting ready to clean the incubator out because I have no idea when that hen may or may not set.

If a hen hatches eggs, you have to watch first time mom's because sometimes they'll attack their own babies when they hatch. I had a turken hen do that before. Sometimes they're klutzy and will step on their babies as well. Other hens are better at taking care of their babies than others. There are variations in the different types too. Don't give your hen too many eggs to cover, or else a cold egg can get rotated back in and can end up having a lower hatch rate. There is no way to bribe a hen to get her to start setting.

If you get a still air incubator that doesn't have an automatic rotation of the eggs, you will need to be on hand to flip the eggs at least 2 times a day. After day 18 you don't need to rotate them as they're getting in position to hatch.

My key west/gypsy hens will set on their eggs once they get 6 in the nest. I try and make sure I gather the eggs cuz if they hit 6 they set and turn into evil spitter, biting broodies and then BAM there's babies everywhere. They will usually aquire another 6 eggs because often, another hen or 2 will also lay in that box lol. It seems like they always hatch at least a dozen lol. Its like they can count!! They also hide their eggs :/ I have 2 incubators but I never use them anymore because I can just use the Key West hens. They are excellent mothers. Lord help anyone/thing that tries to get their babies lol. I've seen them chase down stray tomcats. They r little but fierce.

You can look on Craigslist and make your own incubator from a cheap non working wine cooler. If you do a search on backyardchickens.com there are lots of tutorials on making incubators