Olive or baby oil may be used to "show off" the bare skin, for wrestling or just slipperiness, e.g., to complicate pole climbing. Cleaning may be limited to a dive into water, hosing down or even paddling the worst off. They may have to do tedious cleaning including swabbing the decks or cleaning the toilets with a toothbrush. In fraternities, pledges often must clean up a mess intentionally made by brothers which can include fecal matter, urine, and dead animals. Servitude such as waiting on others (as at fraternity parties) or various other forms of housework, often with tests of obedience. In some cases, the hazee may be made to eat raw eggs, peppers, hot sauce, or drink too much alcohol. Some hazing even includes eating or drinking vile things such as bugs or rotting food. The hazee may have to wear an imposed piece of clothing, outfit, item or something else worn by the victim in a way that would bring negative attention to the wearer. Examples include a uniform (e.g. toga); a leash or collar (also associated with bondage); infantile and other humiliating dress and attire. Markings may also be made on clothing or bare skin. They are painted, written, tattooed or shaved on, sometimes collectively forming a message (one letter, syllable or word on each pledge) or may receive tarring and feathering (or rather a mock version using some glue) or branding. Submission to senior members of the group is common. Abject "etiquette" required of pledges or subordinates may include prostration, kneeling, literal groveling, and kissing body parts. Other physical feats may be required, such as calisthenics and other physical tests, such as mud wrestling, forming a human pyramid, or climbing a greased pole. Exposure to the elements may be required, such as swimming or diving in cold water or snow. Orientation tests may be held, such as abandoning pledges without transport. Dares include jumping from some height, stealing from police or rival teams and obedience. Blood pinning among military aviators (and many other elite groups) to celebrate becoming new pilots is done by piercing their chests with the sharp pins of aviator wings. On a pilot's first solo flight, they are often drenched with water, as well as having the back of their shirt cut off to celebrate the achievement. Cutting off the back of the shirt originates from the days of tandem trainers, where the instructor sat behind the student and tugged on the back of their shirt in order to get their attention.