The purpose of a letter of attestation is to confirm or acknowledge an action, statement or behavior. As such, it takes the format and layout of an official letter, but with a few modifications. Basically, the sender is attesting to the knowledge and awareness of a particular situation.
Some consider L.rubellus to be the true red worm. It is also called the dung worm, or red marsh worm. This worm loves manure and compost piles but has also been found working the earth which makes it doubly effective as the two other worm varieties stay mostly at the surface of the soil.
The temperature of the surrounding environment combines with the moisture level of the bedding and heat given off by organic material as part of composting to determine the exact level of heat or coolness. Use a soil thermometer or compost thermometer, available at garden centers, to measure worm bin temperatures.