Here is what I found out about tunnel nests: http://books.google.com/books?id=Z9...=X&oi=book_result&resnum=1&ct=result#PPA34,M1 (sorry, long link)
I also saw this: Use colony nests. These are essentially big nest boxes two feet by four feet by about 18" high, with a small door about eight inches square. In ordinary nest boxes, two or three hens will jam themselves into a nest meant for one, and this breaks a lot of eggs. Roomier nests lead to less breakage, and colony nests are very dark inside. These are often set directly on the floor in a dark part of the henhouse. They should be ventilated (making a couple of walls out of pegboard is good). Use one for every 40-50 hens. A variant is the tunnel nest, which is two feet wide and eight feet long, with a door at each end. Use one for every 80-100 hens. (http://www.plamondon.com/faq_misc.html)
This tunnel nests don't make sense to me. If there is a hen nesting in the middle of that eight foot span, how many eggs does she step on on her way out? And that colony nest...do chickens enjoys getting together like quilters and laying their eggs?
And then there was this: For laying hens a darkened, raised nesting area with nests containing clean nesting material should be available. Nests can be in the fenced area or in the shelter. The entrance to the nests should be through a covered passageway or tunnel in front of the nests. If the nests are in the shelter the back of the nests should be covered but may be made to open from the outside of the shelter for egg collection. (http://www.canadianpoultry.ca/chapter_i.htm)
I also saw this: Use colony nests. These are essentially big nest boxes two feet by four feet by about 18" high, with a small door about eight inches square. In ordinary nest boxes, two or three hens will jam themselves into a nest meant for one, and this breaks a lot of eggs. Roomier nests lead to less breakage, and colony nests are very dark inside. These are often set directly on the floor in a dark part of the henhouse. They should be ventilated (making a couple of walls out of pegboard is good). Use one for every 40-50 hens. A variant is the tunnel nest, which is two feet wide and eight feet long, with a door at each end. Use one for every 80-100 hens. (http://www.plamondon.com/faq_misc.html)
This tunnel nests don't make sense to me. If there is a hen nesting in the middle of that eight foot span, how many eggs does she step on on her way out? And that colony nest...do chickens enjoys getting together like quilters and laying their eggs?
And then there was this: For laying hens a darkened, raised nesting area with nests containing clean nesting material should be available. Nests can be in the fenced area or in the shelter. The entrance to the nests should be through a covered passageway or tunnel in front of the nests. If the nests are in the shelter the back of the nests should be covered but may be made to open from the outside of the shelter for egg collection. (http://www.canadianpoultry.ca/chapter_i.htm)