My mother lives in a tropical country on the equator. She has a couple chickens now, and has had chickens on and off for the last 25 years, both where she is, and in Texas. Here in the land of winter & summer, we assume that a hen is -more- likely to go broody in spring/summer, than in winter. We also talk about it being their 'hormones' that trigger the broodiness. The following is an interesting email from my Mother; ".... Heti the hen is indeed laying eggs! She has been hiding them so well ..... We found her nest under the veranda of the storage building. So far there are eight little eggs (we can see them through the cracks of the veranda decking). So here is a question for you, Maureen: on your chicken website, did anyone have information on what makes a hen go broody? [the native people] say that it is definitely the number of eggs - if it gets up to a dozen or more, she will start sitting on them. Is this true? I thought it was a seasonal thing!" Does anyone know specific research on the trigger(s) needed for broodiness? What -is- bred 'out' of Leghorns, for example, that makes them 'non-broody' types? Neither my mother nor I have any chicken books...just hands on experience, so we haven't any idea about this.... but it -does- seem random, in that country, as to when a hen hatches a set of eggs.