Despite spending much of their time flying in the air, mosquitoes like to lay their eggs in water. Pools of stagnant water make ideal breeding grounds; mosquitoes congregate, breed, and lay their eggs in these bodies of water.
The eggs will then hatch, and juvenile mosquito larvae will emerge. Left unchecked, these larvae will soon mature into adult mosquitoes. If you discover mosquito eggs or larvae in water on your property, you have the opportunity to stop them from developing into adults.
The most obvious way of dealing with the problem is to get rid of the water. This can be tricky, depending on how much water there is, but if it’s feasible, scooping up the water and dumping it away from your home will take care of the problem. Removing stagnant pools of water will also prevent mosquitoes from laying more eggs.
If removing the water itself isn’t practical, the next best option is a larvicide. Larvicides are chemicals designed to kill larvae without causing harm to other organisms, leaving you with clean, pristine-looking water. However, it’s important to note that larvicide will make water poisonous to humans. If you collect rainwater to use for drinking or cooking, don’t put any larvicide in it.
As an alternative to larvicide, pouring vegetable oil into the water will create a layer on the surface that cuts off the larvae’s air supply. Vegetable oil isn’t toxic to humans, but it isn’t suitable for use in fish ponds as it will prevent the exchange of oxygen between the water and the air, killing any fish. You can achieve the same effect using washing up liquid.
A single drop of washing up liquid is enough to treat a gallon of water. None of these methods is perfect. The only surefire way to eradicate the larvae is to remove the affected water entirely or call in a professional pest controller with specialised equipment.