Some live in fungi. Others feed on carrion. Some beetles are parasitic. Some of the plant-eating beetles are considered to be serious pests to crops. Other beetles are beneficial to mankind because they feed on insects that damage crops.
Beetles can live on or in the ground, on vegetation, or in water.
Beetles tracks can be found in just about as many environments as the beetles themselves. However, some of these environments are not the type that tracks show up in well. The best places I've found to look for beetle tracks are near the water's edge, or in fine silty soil near water. Their tracks are also easy to find in dry, sandy environments. Since most beetles don't weigh much, their tracks can be hard to see.