If you do nothing then the ants and rats and algae will come. They start in the shadows, taking the grime and food and dirt that builds up around the edges. But the more they get away with it, the bolder they will get.
Soon your pool is green. Soon your house has an ant trail marching all the way into the kitchen and back to an underground nest. Soon the rats are so emboldened they find a way into your dustbins, your garage, your car.
Atrophy is the enemy. His best friends are algae, ants and rats. Fight back.