Mud

Mud(probably fromMiddle Low Germanmudde, mod(de)'thick mud', orMiddle Dutch)isloam,siltorclaymixed withwater. Mud is usually formed afterrainfallor near water sources. Ancient mud deposits hardened overgeological timeto formsedimentary rocksuch asshaleormudstone(generally calledlutites). When geological deposits of mud are formed inestuaries, the resultant layers are termedbay muds. Mud has also been used forcenturiesas aconstructionresource for mostly houses and also used as a binder. AnOld Englishword for it wasfen, now inmost dialectsreferring to a type ofwetland.
In theconstructionindustry, mud is a semi-fluid material that can be used to coat, seal, or adhere materials.The term "mud" can be used for various semi-fluid materials used in construction includingslurry,mortar,plaster,stucco, andconcrete.
Mud,cob,adobe,clay, and many other names are historically used synonymously to mean a mixture ofsubsoiland water possibly with the addition of stones,gravel,straw,lime, and/orbitumen. This material was used a variety of ways to buildwalls,floorsand evenroofs. Forthousandsofyearsit was common in most parts of theworldto build walls usingmudbricksor thewattle and daub,rammed earthorcobtechniques and cover the surfaces with earthen plaster.
Mud can be made into mud bricks, also calledadobe, by mixing mud with water, placing the mixture intomouldsand then allowing it to dry in openair.Strawis sometimes used as abinderwithin thebricks, as it makes them acomposite. When the brick would otherwise break, the straw will redistribute the force throughout the brick, decreasing the chance ofbreakage.Such buildings must be protected fromgroundwater, usually by building upon a masonry, fired brick, rock or rubble foundation, and also from wind-driven rain in dampclimates, usually by deep roof overhangs. In extremely dry climates a well-drained flat roof may be protected with a well-prepared (puddled) and properly maintained dried mud coating, viable as the mud will expand whenmoistenedand so become more water resistant.Adobe mudbricks were commonly used by thePuebloIndiansto build their homes and other necessary structures. In some countries there are entire cities made of mud brick houses.Cow dungandbiomassare added to regulate indoor climate.
Mud that is mostly clay, or a mixture of clay and sand may be used forceramics, of which one form is the common firedbrick. Fired brick are more durable but consume much moreenergyto produce.
Stabilized mud (earth, soil) is mud which has had a binder such as cement or bitumen added. Examples aremudcrete, landcrete, andsoil cement.
Pottery is made by forming aclay bodyinto objects of a required shape andheatingthem to hightemperaturesin akilnwhich removes all the water from theclay, which induces reactions that lead to permanent changes including increasing their strength and hardening and setting their shape. A clay body can bedecoratedbefore or after firing. Prior to some shaping processes, clay must be prepared.Kneadinghelps to ensure an even moisture content throughout the body.Airtrapped within the clay body needs to be removed. This is called de-airing and can be accomplished by amachinecalled a vacuumpugor manually bywedging. Wedging can also help produce an evenmoisturecontent. Once a clay body has been kneaded and de-aired or wedged, it is shaped by a variety of techniques. After shaping it is dried and then fired.
Inceramics, the making of liquid mud (calledslip) is a stage in the process of refinement of thematerials, since larger particles will settle from theliquid.
Mud can provide a home for numerous types of animals, including varieties ofworms,frogs,snails,clams, andcrayfish. Other animals, such ashippopotamuses,pigs,rhinoceroses,water buffaloandelephants,bathein mud in order to cool off and protect themselves from thesun. Submerged mud can be home tolarvaeof variousinsects.
Mud plays an important role in themarine ecosystem. The activities ofburrowinganimalsandfishhave a dramatic churning effect on muddyseabeds. This allows the exchange and cycling ofoxygen,nutrients, andmineralsbetweenwaterandsediment.
Below the surface, the burrows of somespeciesform intricate lattice-like networks and may penetrate ameteror more downwards. This means that the burrowed mud is a productivehabitat, providingfoodand shelter for a wide range of mud-dwellers and other animals that forage in and over the mud.
Mud can pose problems for motortrafficwhenmoistureis present, because everyvehiclefunction that changes direction orspeedrelies onfrictionbetween thetiresand theroadsurface, so a layer of mud on the surface of the road or tires can cause the vehicle tohydroplane. People and cars can also become stuck in mud, as inquicksand.
Heavyrainfall,snowmelt, or high levels ofgroundwatermay trigger a movement ofsoilorsediments, possibly causingmudslides,landslides,avalanches, orsinkholes.Mudslidesinvolcanicterrain (calledlahars) occur aftereruptionsasrainremobilizes looseashdeposits.Mudslides are also common in thewestern United StatesduringEl Niñoyears due to prolonged rainfall.
Geophagiais the practice of eating earth or soil-like substances, also known as geophagy, and is practiced by some non-human primates and by humans in some cultures. In other human cultures it is considered an eating disorder and classed asPica.
Mississippi mud pieis a chocolate based dessert pie.Mud cookies(baked from literal dirt mixed with oil, water, etc.) are also eaten in the poorest parts ofHaiti.  Children's recipes for "mud" also exist, which is generally achocolateorcornstarch-based sludge used more for visual appeal than actual taste. However, it does not contain real mud."Mud" is also a colloquialslangword forcoffee, especially when thick, strong, and/or dark.
A mud bath is a bath of mud, commonly from areas where hot spring water can combine withvolcanic ash. Mud baths have existed for thousands of years, and can be found now in high-endspas.
Mud wallows are a common source of entertainment forchildren. Mud wallows can be any shape, size, depth and some can havewateras well as mud. Usually wallows are shallow dips in the ground that have beenfloodedand were full ofdirtand those two have mixed to make a squishy mud wallow.
Mud sports are sports that take place in, or heavily incorporate, mud.Examples include: