Yes. Mosquitoes in this country usually bite during dusk to dawn hours. However, if you travel internationally, you may encounter mosquitoes that are active during the day as well. Stay indoors if possible, when out, leave as little of your body uncovered by clothes. Then use deet containing mosquito repellents, such as ultrathon, on all exposed body parts and wear clothes pre-treated with permethrin.
Natural options. If you are looking for a natural repellent for mosquitoes consider citronella, lemon eucalyptus oil, soybean oil, geranium oil, clove oil or fennel.
Yes! Repellents containing ~30% deet or ~10% picaridin are safe and effective. Other "natural" products (eg: eucalyptus or lemongrass oil) work, but don't last near as long. Bed nets work wel, although can be a little warm to sleep under. Permethrin is an insecticide which you can use to treat nets and outer layers of clothing effectively killing mosquitoes before they bite you. L.