While it won’t harm a mammal, to something as small as an insect the Diatomaceous Earth is abrasive. Warning: it is also abrasive to reptiles, so do not put it on them! The DE sticks to insects that walk over it and rubs off their protective waxy coating. Once the coating has been removed, they rapidly lose all of their body moisture. The bugs literally dehydrate to death. This may seem mean, but when you have dealt with a flea infestation or bed bugs no mercy shall be had.
In order to kill bugs, simply sprinkle where the insects are found. For example, if you are trying to deal with fleas on your pet and in your house, rub DE all over your pet (not in their eyes or nose, they may cough) and sprinkle around carpets, beds, and baseboards. Make sure to get down to the skin on those long-haired breeds! DE is also an effective ant killer as well.
DE is also used for killing internal parasites, such as round worms. The DE damages the intestinal worms, causing them to die and be expelled. Simply feed a tspn or so for a week to kill internal parasites!
DE binds toxins in ingested items and in the colon while it passes through the digestive tract. The bound toxins can then pass through the body safely, before causing damage. For example, DE was used to decrease fungal toxicity in chickens , as well as reduce radiation poisoning in humans.
Calcium is an important mineral for bone and joint health. A study by K. R. Martin  showed that consuming silica leads to increased bone mineral density. This means more calcium being absorbed and deposited in bones for a stronger, healthier skeleton!