How to protect against mosquitoes The state DPH and the Newbury Board of Health urge residents to take important steps to protect themselves against mosquito-borne illnesses, such as West Nile virus. These steps include: Apply insect repellent when outdoors and use a repellent with DEET. DEET products should not be used on infants under two months of age. Be aware of peak mosquito hours. The hours from dusk to dawn are peak biting times for many mosquitoes. Consider rescheduling outdoor activities that occur during evening or early morning. Wear long-sleeved clothing, long pants and socks when outdoors during peak mosquito times. Drain standing water. Mosquitoes lay their eggs in standing water. Limit the number of places around your home for mosquitoes to breed by either draining or discarding items that hold water. Check rain gutters and drains. Empty any unused flowerpots and wading pools, and change water in birdbaths frequently. Install or repair screens. Keep mosquitoes outside by having tightly fitting screens on all of your windows and doors.