We have a standard grass lawn and in true British style got a paddling pool out a month too early. The pool got infested with mosquito larvae so we drained it (not into the garden) and got rid of the pool.
When we removed it we found that mould(?) had grown where the pool had been. It's definitely got two different areas of colour. After a couple of days these holes also appeared, I'm assuming it could be from birds. Any idea what this is and what we should do?