Rotary drilling rig digging water wells

The standard method involves percussion drilling in which a drill is alternatively raised and dropped in the descending borehole. It is suited to the drilling of wells in any material from soft clay to the hardest rock. [pdf]

Electric rock drill digging bees

The most common species of ground bee — Colletes inaequalis— is a black and tan-colored bee with a black abdomen and tan stripes. These ground nesting bees can be identified by their fuzzy tan-colored. [pdf]