Several weeks ago, after coyotes killed several of my chickens I decided to try my hand at incubating some eggs. I had an old incubator in my classroom that I'd never used. I bought an automatic turner and a thermometer/barometer thingy. For 5 days I tried to get a constant temperature. NOPE! But I got CLOSE! I put in 15 of my eggs and 20 from a friend. Could I maintain a constant temp? NOPE...somedays it was 95, some days it was 105. Could I maintain any sort of humidity? NOPE...it averaged 40 percent. I added water cups, I opened the lid too many times, just to have a little peek... On the 18th day, I snatched the top off, zoomed the eggs out, jerked the auto turner out and the wire screen in, and zoomed the eggs back in. On the morning of day 21, THERE WAS A CHICK!!! Then there were 4...then 11...then 19! It was like that old Star Trek episode "The Trouble with Tribbles". I finally ended up with 21 chicks! I never dreamed, after all my mistakes, that any would hatch. I was hopeful that I might get 3 or 4 just for the experience of hatching. Thank God that Mother Nature is smarter than we are! I love this chicken thing!!!