Unforgotten buckets left to collect rain water can be perfect places for mosquitoes to lay their eggs. The small amount of water that accumulates in discarded tires is deep enough for mosquitoes to carry on generations.
How shallow are we talking? Only a 1/4 inch or so is all the water that’s needed for a mosquito to lay her rafts of eggs on the water’s surface. As long as the water is still or stagnant mosquitoes will find and use the smallest puddles that can’t be used for much else.
Take this shallow indentation in a plastic chair. Rain water collected in the seat of the chair and was left to lay. Algae grew, leaves and dirt collected in there, and eventually a mosquito found her quarry.
Even though the depth of the water was minimal the stagnant puddle was perfect for laying eggs.
Watch this video showing how mosquito larvae wriggle around in the shallow water.
Shortly after that video was taken the chair was tipped over to remove the standing water. To reduce the mosquito population around your house, make sure to tip over any buckets or other objects that can collect rain water.