Yes, they can lay both non fertile eggs and fertilized eggs depending on the availability of a rooster and a successful mating. Since roosters deposit a sperm sac rather than having to mate each time a mated hen can produce fertile eggs for up to 10 days after one mating.
To make unfertelized eggs the chickens are kept separate from the rooster because they don't need to have intercourse to produce eggs. The same applies to humans, women don't need to participate in intercourse to have a period. (P.S. humans release eggs too)
When its just fresh there's no telling. After the hen has been sitting on it or has been in an incubator you can tell be holding it against a bright light (you can see blood veins in the egg) or put it in water; a fertilized egg will float, and a non fertilized egg will sick. A spoiled/ rotten egg will float as well, but it will be quiet old when that happens.
Absolutely nothing if you are not incubating the fertilized ones. There is no visible difference, no nutritional difference and no taste difference.
The same amount of time it takes to lay a non fertile egg. A hen can only produce ONE egg every 24 hours maximum. No breed of chicken produces faster than that. Many take longer than 24 hours to lay and egg.
The cost of fertilized chick eggs can vary depending on the breed, quantity, and where you purchase them from. On average, you can expect to pay around $2-$5 per egg. It's recommended to buy from a reputable breeder or supplier to ensure healthy chicks.
The egg came first. Eggs have been laid by animals for hundreds of millions of years, while chickens, as we know them today, evolved from non-chicken ancestors through a gradual process of change.
No, non-identical twins are fraternal twins. They are created when two eggs are fertilized at the same time and become embryos. Identical twins are when a fertilized egg splits into two on its own.
Eggs sold in stores are typically unfertilized, meaning they will not develop into chicks even if incubated. Only fertilized eggs contain the genetic material needed for embryonic development and hatching. Commercially produced eggs for consumption are not fertilized.
If two eggs were released but only one was fertilized, the fertilized egg would begin to develop into an embryo, while the unfertilized egg would simply be shed during the menstrual cycle. The body would typically recognize the unfertilized egg as non-viable, leading to its eventual expulsion. As a result, only the fertilized egg has the potential to develop into a pregnancy.
Hens instinctively brood and will sit on non fertilized eggs. Make sure you remove any eggs she has gathered under herself and keep moving her off the nest. This may take days to work but repeated disturbance to her dreams of hatching a non fertile clutch will eventually work.
Most snails are hermaphrodites (not male or female, but both), and some can even fertilize their own eggs. It's probably safe to assume that if you see the snail eggs, they are fertilized, and will probably hatch in 1-2 weeks if left alone.
In a literal sense, the chicken. Without the hen, the egg could not be formed nor laid. Therefore, the hen must come first. The question that comes soon after is "Then how was the hen born?" The fact of the matter is chickens were not born, they evolved from other creatures; the chicken has been "in the making" for millions of years. So, in a technical sense, the egg came before the hen; the only thing that came before the chicken was non-chickens, therefore the mutations/combinations had to have occurred inside the egg which gave birth to the hen.