Permethrin and tetramethrin are non natural, non organic controls of pest populations. They share membership in the same chemical control group, the pyrethroids. They control insect populations by attacking each individual insect's nervous system. They're particularly effective against such stubborn pests as cockroaches and mosquitoes.
But there are differences between the two. Permethrin is considered to be of low toxicity to mammals. It's absorbed poorly by the skin. In contrast, tetramethrin is very potent.
An artificially produced insecticide, orignally derived from an extract of Chrysanthemum flowers.
A termite protection product
You can get rid of sand gnats by treating the area with product such as permethin. An exterminator can also help to rid sand gnats with proper treatment.
Need to treat the area using a product called permethin. this should be available from a feed store. Treat the area again in about 7 to 10 days
=== === Is this bug super tiny with a brown spot on one end? If so hes called a no-see-em. They can be killed by rubbing your hand over the skin where they are. Is this bug similar in size and shape to a housefly? If so, its a deer fly. Hard to kill without a flyswatter. Both bite. The deer fly can carry disease though. Insect repellant works for both but the pool water washes it off too easily. they are called thrips and thay are hard too kill so try finding an insecticide with permethin the best i found is tall star