The national parks close at sunset, so a night drive is only possible in private concessions and game reserves on the park boundaries — which is precisely why those concessions are worth staying in.
After dinner you head out with a spotlight fitted with a red filter, which does not dazzle the animals. What comes out is entirely different from the daytime cast: genets, civets, bushbabies, aardvark, porcupine, white-tailed mongoose, spring hares, owls and nightjars, and above all the big cats, who do the great majority of their hunting after dark.
Drives usually last two to three hours. Take a warm jacket — the plains drop sharply once the sun is gone.