we collect between 1 and 2 dozen eggs a day (and we hoard egg cartons, so call me if you have any spares). our hens lay brown eggs, as most breeds do. supermarket eggs are usually white because most commercial breeders use the same breed of high-capacity laying hens - white leghorns. this, combined with the decline in the number of backyard flocks, has pushed a few chicken breeds to the verge of extinction. some of the chicks we keep (orpingtons, wyandottes and brahmas) are on the endangered list. i'm concerned about the loss of diversity in the food supply, but more on that later (let's stick with eggs for now).
more egg trivia (more than you probably want to know)...
hens start laying at about 22 weeks of age. some breeds are better layers than others, but most young hens will lay an egg a day in summer. laying decreases as they get older.
a hen's laying cycle is based on light. they need a certain amount of continuous light to produce an egg, which is why they lay more eggs in the summer and less in winter. it's also why commercial egg producers use artificial light - creating an artificially long "day" and short "night" - to increase laying frequency (which is hard on the hens). the natural drop in winter egg production gives the hens a "hiatus" that their bodies need.
hens don't need a rooster to lay eggs, they only need one to fertilize them. you'd be surprised how many people don't know this. a hen that's inclined to sit on eggs to hatch them is described as "broody". a hen will usually sit on a nest that's accumulated 4 or more eggs, though some of ours will go "broody" on a nest with no eggs at all (even though i've explained the futility of this). it takes about 21 days to hatch a chick.
hens add a natural coating to the outside of their eggs which makes them non-porous and resistant to bacteria. the coating also keeps them fresh longer, and allows them to be stored unrefrigerated (which is how most of the world stores their eggs - surprise!). commercial egg producers wash their eggs before sale, and add a thin sealant (usually mineral oil). since the sealant is not as effective as the natural stuff, these eggs must be refrigerated to avoid spoilage.
if you crack an egg and see a red, brown or darkish spot near the yolk, it isn't an embryo - it's from the hen. sometimes tiny blood vessels burst in the oviduct, which can cause a spot in the egg (i know - yuck! - but it's perfectly safe to eat).
older eggs are better for hard-boiling. fresh eggs are harder to peel because the whites have not aged enough to separate from the shell. learned this the hard way making deviled eggs for a party (at least they tasted good!).