There are thousands of cacti species that exist in the wild, but they usually fall into two main categories, desert and forest. You can identify desert cacti by their many spikes or spines. And forest cacti have little to no spikes or spines, like the holiday cacti. Because they are native to South America, they want to be in the brightest spot in your home, requiring bright indirect light and some direct light. They like an extremely well-draining soil mix such as a cactus soil mix with added perlite or orchid bark. Some cacti even bloom! If your indoor cacti produce flowers, they are very happy.