As with all little pieces of paradise, there is inevitably a party-spoiler that you should be prepared for, and in so doing, it won't be too much of a bother.
The first thing to note is that Zambia is a malaria area so you should make sure that you take malaria prophylactics and pack mosquito repellent. It is also a good idea to bring comfy long trousers and a long-sleeved shirt for the evenings and early mornings when mossies are at their most energetic.
All of the National Parks have tsetse flies - an insect similar to a horse-fly with quite a mean bite. Tsetse flies can carry sleeping sickness and some people can experience an allergic reaction which can be unpleasant and painful but in general, other than an annoying bite, most people won't feel any further effects. Tsetse flies seem to occur in pockets and are particularly attracted to Mopane woodland thickets, and are more evident at the start of the season and during the rains. Camps are positioned well away from them but you may drive (rapidly) through areas on drives. For some reason, tsetses love dark colours like blue and black, so avoid wearing these when out on drives. You may see fabric traps of similar colours out in the bush to help control them where they are especially bad.
All insects generally come out with the rains so the emerald season will be the worst time to visit if you have a particular aversion to insects. June and July are probably the best in terms of low insect numbers.
There are poisonous snakes in Africa and you should keep an eye out while you are walking out and about or around camp. In general, snakes like the look of you about as much as you like them and will get out of your way pretty smartish. If you do see a snake, keep your distance and let someone know and the staff will deal with it if necessary or shoo it away if it is unlikely to be a nuisance.
Posted by: Alex