Cicadas have a 17-year or 13-year life-cycle, depending on the variety.
A leap year, which occurs once every four years, is when the month of February has 29 days instead of 28. When the calendar was created a year was noted to be 365 and one fourth days long. Rather than have a fourth of a day every year, one full day every four years was added.
a cougar can have 1 to 6 cubs, but usually they only have 3 once every 2 years
Veterinarians measure dog age by the following formula: From birth to age one, your dog goes form birth to (human) 21 years old. For every year thereafter, your dog ages four human years. Hence, for the first year of your dog's life, every human month is about two years, or a little less. Once your dog has passed it's first birthday, every human month is about three dog months.
Blue moons occur about once every 2.7 years, which is the occurrence of an extra full moon in a season. The term "blue moon" does not refer to the actual color of the moon; rather, it is a unique celestial event in the lunar cycle.
Female turtles (all species) come ashore once a year to dig a hole on the beach in which to lay their eggs.
A hurricane's name comes up for reuse once every six years unless it is retired.
I heard that it comes every 400 years.
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No, you are not an alcoholic if you get drunk once a year and you are not an abuser if you call someone a name once every five years.
Jupiter orbits the Sun once every 11.9 Earth years, Saturn once every 29.5 Earth years, Uranus once every 84 Earth years, and Neptune once every 165 Earth years.
Yes. Normally a hurricane name can be re-used once every six years.
Biennial is once every two years. Biannual is twice every year.
a leap year
Every ten years=once a decade
Every four years.
A soccer world cup happens once every 4 years. The next World Cup is in 2010.
i think it comes past the earth every 76 years.