`` up to the age of eight months he 's a pewmet , then he 's a c*ck until fourteen months , and then he 's a snood- '' captain vimes sat entranced , eating the horrible cake , britches gradually dissolving , as the stream of information flooded over him ; how the males fought with flame but in the laying season only the hens* breathed fire , from the combustion of complex intestinal gases , to incubate the eggs which needed such a fierce temperature , while the males gathered firewood ; a group of swamp dragons was a slump or an embarrassment ; a female was capable of laying up to three clutches of four eggs every year , most of which were trodden on by absent-minded males ; and that dragons `` only until their third clutch , of course .