For many years now it has been known and proven by many manufactures that termites and ants will sometimes attack a vinyl swimming pool liner. It is suspected that termites are attracted to the pool area due to the dampness in the soil around the pool.
Usually the first signs are very small holes in the liner above the water line. The liner may have dozens of holes in it within a short period of time after they have begun their attack.
Most of the time if the liner is taken out of the bead track and pulled away from the wall you may see trails that the termites have left behind. Usually the holes are small, about an eighth of an inch to a quarter of an inch in diameter and are round or oval shaped.
When a pool liner has been attacked by ants or termites, the homeowner is advised to get an exterminator to treat the ground beneath the pool and the area around the perimeter of the pool deck when the swimming pool liner is replaced.
Termites and ants are typically in places where there is wood. Some common places they may be are: where a patio or walkway was removed, around flower pots or planters, around a wooden fence near a pool, and close to tree stumps or where a tree has been removed.