A year containing an extra day. It has 366 days instead of the normal 365 days. The extra day is added in February, which has 29 days instead of the normal 28 days. Leap years occur every 4 years. 2016 is a leap year and so is 2020. Except that every 100 years special rules apply.
Best Answer: A average life span is about 1 year. Some live only 3 months, but others can live up to a couple of years. The lifespan of the average tick is about two years. Source(s): http://www.nyc.gov/html/doh/html/ehs/ehs... A fly is 3 days so i'm guessing somewhere around the lines of there.
Life expectancy is defined as the average number of years a population of a certain age would be expected to live, given a set of age-specific death rates in a given year. Healthy People 2020 monitors 2 life expectancy measures: Life expectancy at birth. Life expectancy at age 65.