Just to clarify, insect repellants do not kill insects. They repel them. They hold off, fend off, and ward off insects, specifically mosquitoes. Insects repellants help reduce exposure to harmful mosquitoes, thus minimizing the risk of acquiring deadly ailments.

Insect repellants work by decreasing the skin odor of a person making him unappealing to the insect's senses. Insect repellants should be applied and re-applied after swimming or sweating.

Insect repellants that have a higher percentage of the active ingredients provide longer protection. These active ingredients are chemically known as N,N-diethyl-meta-toluamide or DEET and KBR 3023 or Picardin. Based on a study conducted in 2002, products containing 23.8% DEET provide protection for 5 hours. 20% DEET provides 4 hours of protection. 6.65% provides 2 hours of protection, and so on and so forth. In short, the lesser the concentration, the less protection it provides.

In some rare cases, the use of insect repellants can cause skin irritation. Immediately stop the use of this product and find an insect repellant with a lesser concentration of the mentioned chemical substance. If irritation still persists, completely stop using insect repellants.

Since insect repellants are often used outdoors, another main concern is if people can also apply sunscreen when they have already applied repellants and vice-versa. Simply follow the instruction on the proper usage and application of both. However, the combination of both insect repellant and sunscreen in one bottle is not highly advisable because the use of these two different substances is totally different. You do not reapply your insect repellant as often as you reapply your sunscreen so be extremely careful in case you have seen a product that offers this feature.