To grow up, produce swarmers, make new colonies.

Maturity is commonly said to be reached when the colony can reproduce. From the time that the founding pair first mate to the colony producing winged adults, and releasing them to become a new generation, sometimes takes as little as three years but can be much longer, depending on the species and conditions.  The winged termites (also known as swarmers but correctly as alates) don’t appear until the colony has grown substantially.  Usually several generations of offspring develop as generic workers and special soldiers, building a nest system and grow their numbers before the first termites are allowed to develop the wings and other bits needed for reproduction.  For the main subterranean pests, these emerging colonies may go unnoticed (even with the best inspections). A colony of subterraneans is often closer to seven years old before there is any major surface evidence to see.  If food is poor or water is hard to get, the colony may grow slowly and weakly.  In the warm, wet tropics (think Honolulu, Miami or Manila) a colony can grow much more quickly than it can in cooler places (like Paris, Chicago or Canberra).  With insects, being cold-blooded, effective time varies with temperature, it races in the heat and crawls in the cold, so it is next to impossible to provide an accurate estimate for any given colony.