African vlei rats (Otomys), also known as groove-toothed rats, live in many areas of sub-Saharan Africa. Most species live in marshlands, grasslands, and similar habitats and feed on the vegetation of such areas, occasionally supplementing it with roots and seeds. The name "vlei" refers to the South African term for intermittent, seasonal, or perennial bodies of standing water. Depending on the species adult Otomys have a body length between 12 and 22 cm (5–9 inches) and weigh 90 to 260 grams (3–9 oz).