If you're visiting a hot country, the chances are you're going to have problems with mosquitoes - and if you're in equatorial zones then the risk of malaria is very real. If you're exploring temperate areas like the west coast of Scotland or the south-west South Island of New Zealand in the wrong season, then the midges and sandflies will make the mosquitoes look positively benign.
The conventional way to get rid of nasty biting insects is to smother the body in chemicals, the most effective of which is the compound DEET (so check the ingredients of your repellent - the more DEET, the more effective the repellent). However, overuse of DEET can be harmful, especially on children, and although the ill effects of DEET are preferable to catching malaria, you might want to consider alternative methods of repelling insects if you're on the road for a long time.
The most sensible way to prevent insect bites is to wear light-coloured clothes, as mosquitoes prefer dark clothing. Although a dedicated mosquito will hammer its way through thin cotton clothes in no time at all - and with the huge mozzies found in places like northern Australia even jeans are no protection - sandflies and midges can't get to your skin and therefore can't bite. The critters are worst at dusk and at dawn (this is the only time that malarial mosquitoes bite), so getting in the habit of wearing long trousers, socks and long-sleeved shirts at these times of day can save you considerable discomfort. As a bonus, in many countries it is considered rude to show off your bare legs, arms or torso, so you'll get a smoother and more pleasant travel experience by wearing long clothes anyway.
Sleeping under a mosquito net is also a good move. Make sure you buy the biggest one you can, and tuck it under the mattress all round the edges of the bed. Not only will this keep out mosquitoes, it'll stop you being woken up by flies crawling up your nose, prevent that lizard from crawling up your leg, and make it harder for a thief to get at the passport you've cunningly stashed under your pillow.
If you're heading out into the outside world and you need more protection than long clothes can offer, then there's a highly effective bushman's recipe to repel mozzies, midges and sandflies. Get a plastic bottle and fill it half full with the following mixture:
- 70% Johnson's Baby Oil
- 30% Dettol (or an equivalent disinfectant that doesn't cause skin irritation)
The two layers will not mix, but if you shake the bottle (hence filling it only half full) the two will mix into an emulsion not unlike a chemical vinaigrette. You can then smear the mixture over the exposed parts of your body. It works because mosquitoes simply hate the smell of Dettol, so they land on your skin and take off immediately before they have time to bite; and sandflies and midges, being little buggers, land on your skin and simply stick to the baby oil, which also provides a layer that their tackle can't get through. Then there's the added advantage of the baby oil helping to protect your skin from wind and dehydration.
If you're in a particularly mosquito-ridden area then you can increase the proportion of Dettol to 50%, but it's slightly less pleasant to use and will begin to repel humans as well as insects.