If ticks continue on cattle until cold weather and then finally disappear it should be borne in mind that in all probability eradication has not been accomplished and that there may be engorged females, unhatched eggs, and inactive seed ticks on the farm or range, and that even if the cattle should remain free of ticks during the winter they may become reinfested the following spring.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler
For every fifteen birds removed, the heat in egg-chamber is reduced at least one degree, as you are removing so many little stoves, and if the machine is not gauged higher, to correspond with the number of ducklings taken out, the result will be fatal to the unhatched eggs.
"Natural and Artificial Duck Culture"
James Rankin
It contained a young bird and one unhatched egg.
"The Nests and Eggs of Indian Birds, Volume 1"
Allan O. Hume