The age of a tree goes Young, Mature, Old, Very old, Overaged. To examine the age of a tree, right click the tile that the tree is on and examine it, the age will show up in the event box.
Cutting down a young or mature tree will yield a very low amount of wood and will be a waste of a tree. Optimum time to cut down a tree is when it is either old, or very old. Some over-aged trees can be [[prune|pruned]] to return them to very old status.
When it comes to the ages of animals, the ages are Young, Adolescent, Mature, Aged, Old, Venerable. Animals take several months to reach the venerable stage. Animals will eventually die of old age, but most species have extremely long lifespans. One [[huge spider]] was observed alive after over six months of real time.