The most effective form of mosquito repellent on the market today is DEET (or N,N-diethyl-meta-toluamide). DEET is a synthetic chemical which, when sprayed on skin and clothing, makes humans unattractive to mosquitoes. DEET is usually added to many popular brands of insect repellents such as OFF! This product can be purchased in most grocery stores and drug stores in recommended concentrations of 30% or less. Overexposure to DEET can cause dizziness and allergic reactions and it is important to know that DEET products with more than 10% concentration should never be used on children. DEET products are available in aerosol sprays, pumps, lotions and moist towelettes for between $5 and $25 online.