Insects, colonizers by their own means
Most of the living beings described so far are organisms that would reach an abandoned pool dragged by the wind, dry leaves or the entry of other animals. However, there are many other animals that can find their habitat in a pool by deliberately entering, among them, insects are probably the most striking.
Apart from visiting insects that only come to the pools to drink water or look for food, such as wasps, many insects lay their eggs in the water, and their larvae reside at the bottom or on the surface. Dragonflies, stone flies… however, most prefer clean and well-oxygenated water, conditions that do not usually occur in an unattended pool.
In this type of stagnant water, the most common insect larvae are mosquitoes. Some, like the tiger mosquitohave found in these environments an ideal place for breeding and today they are an invasive species in Spain.
But the insects most likely to inhabit a pool—sometimes even well-maintained, treated pools—are beetles. There are almost 500 different species of aquatic beetles in mainland Spain, belonging to 12 different families, and most of them can colonize swimming pools.
Finally, and if the pool is left long enough, frogs, newts, snakes and other vertebrates can colonize it.
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