An internal-combustion engine needs four things to run. They need fuel, mixed with air, in a ratio of 14.7 to one. An ignition-spark lights the fuel and air mixture, creating combustion. Compression of the fuel and air mixture makes it explosive. The final necessity is proper timing, of the components.
1 The length of time it takes for eggs to hatch after incubation begins depends on the species and temperatures. 2  For bluebirds, it USUALLY takes about 12-14 days from the date the last egg was laid.3  Different species have different incubation periods, which can vary within a species due to temperature inside the nestbox. Depending on when incubation begins (on the last, or next to last egg), eggs in the same nest can hatch a day or several days apart. 2  It also takes a while for the bird to break through the shell. 3  It could be a new egg from a subsequent nesting if you didn't clean the box out immediately after the last fledging.
baby chickens cheep after the hatching i thought... but you did do great incubating them for the full 21 days. and it shows because day 21 is the day the eggs are supposed to start wobbling around, err the chicken is just trying to get out of the egg, which means you successfully incubated fertilized eggs.ut you did do great incubating them for the full 21 days. and it shows because day 21 is the day the eggs are supposed to start wobbling around, err the chicken is just trying to get out of the egg, which means you successfully incubated fertilized eggs.