Standard deviation from ungrouped data. The standard deviation is a summary measure of the differences of each observation from the mean. If the differences themselves were added up, the positive would exactly balance the negative and so their sum would be zero. Consequently the squares of the differences are added.
A pissant, also seen as piss ant or piss-ant, refers to a specific type of ant. The word is also used as a pejorative noun or adjective, indicating insignificance.he original pissant is any of a certain group of large ant species, commonly called wood ants, that make mounded nests in forests throughout most of Europe.
The ghost ant (Tapinoma melanocephalum) gets its name from its size and pale color of its legs and abdomen, which make it difficult to see. These ants have dark heads and thoraxes.The workers are about 1.3 to 1.5 mm long. Ghost ants are related to odorous house ants.he workers also gather insects to feed the colony. When they are indoors, ghost ants usually prefer sweets. Outdoors, ghost ants make their nest in the ground. They often nest beside stones, logs and firewood piles.