Mud

Ancient mud deposits hardened over geological time to form sedimentary rock such as shale or mudstone (generally called lutites).

[2] The term "mud" can be used for various semi-fluid materials used in construction including slurry, mortar, plaster, stucco, and concrete.

[2] Mud, cob, adobe, clay, and many other names are historically used synonymously to mean a mixture of subsoil and water possibly with the addition of stones, gravel, straw, lime, and/or bitumen.

For thousands of years it was common in most parts of the world to build walls using mudbricks or the wattle and daub, rammed earth or cob techniques and cover the surfaces with earthen plaster.

Pottery is made by forming a clay body into objects of a required shape and heating them to high temperatures in a kiln which removes all the water from the clay, which induces reactions that lead to permanent changes including increasing their strength and hardening and setting their shape.

Mud can provide a home for numerous types of animals, including varieties of worms, frogs, snails, clams, and crayfish.

Other animals, such as hippopotamuses, pigs, rhinoceroses, water buffalo and elephants, bathe in mud in order to cool off and protect themselves from the sun.

[7] Mud can pose problems for motor traffic when moisture is present, because every vehicle function that changes direction or speed relies on friction between the tires and the road surface, so a layer of mud on the surface of the road or tires can cause the vehicle to hydroplane.

Heavy rainfall, snowmelt, or high levels of groundwater may trigger a movement of soil or sediments, possibly causing mudslides, landslides, avalanches, or sinkholes.

Mudslides in volcanic terrain (called lahars) occur after eruptions as rain remobilizes loose ash deposits.

[8] Mudslides are also common in the western United States during El Niño years due to prolonged rainfall.

Children's recipes for "mud" also exist, which is generally a chocolate or cornstarch-based sludge used more for visual appeal than actual taste.