Sheaths also swell as a result of being dirty.. Horses with large beans (accumulations of secretions at the end of the penis) and large accumulations of sheath smegma (normal pasty secretion) often swell. Horses that urinate into their sheaths tend to have dirtier sheaths and more problems with swelling.
Some people think Alaska has less sunlight than other places. The opposite is true. Averaged over an entire year, Alaska gets 10-17 minutes more daylight per day than the rest of the country. If you include civil twilight, Alaska gets 40 minutes more light on average than the rest of the country.
This phenomenon of more daylight than night is not unique to the poles. In fact, at any given time slightly more than half of the earth is in daylight. The 24 hours of summer daylight is known as the midnight sun that is famous in some northern and southern countries.