the first chicken i have ever had go broody was a leghorn, she went broody a few times when i had her then she went to live with a friend of mine and she goes broody every other month but then is not a good mom. i have also had a ee go broody. if a leghorn can go broody any bird could go broody lol. i can see a comet going broody.Urban, maybe she just wants to sleep in the nest box, I know mine do! If they have light enough to see, sometimes they will go back to where they like it best. I don't hear about comets going broody too often. Having said that, I haven't heard of leghorns going broody. I have a leghorn mix, that acts like she is. I kicked her off of the nest today after she had been sitting on her egg for a while. It is cold out there..only 12 degrees right now, I'm sure many are in a box, but I don't bother in the winter, because they can see to get back in the box. Just watch her tomorrow...and notice if she is making a different sound, a cluck, cluck sound. You will know if it's different.And, if she doesn't want to get off of the egg she laid. Good luck!