House centipedes (Scutigera coleoptrata) are common household arthropods recognized by their numerous long legs and remarkable speed. Many people wonder if these multi-legged inhabitants can navigate aquatic environments, specifically if they possess the ability to swim or survive in water. This question often arises when they are unexpectedly found in sinks or bathtubs.
Their Relationship with Water
House centipedes generally cannot swim effectively or survive for extended periods when submerged in water. If a house centipede falls into water, it typically struggles to move and quickly becomes waterlogged. Their movements in water are often erratic and inefficient. Prolonged exposure to water can lead to their demise, as they are not adapted for aquatic respiration. They may be found trapped in bathtubs or sinks because they cannot easily climb the slippery, smooth surfaces to escape.
Why They Avoid Water
House centipedes are ill-equipped for aquatic life due to their respiratory system and leg structure. House centipedes breathe through a network of tubes called tracheae, which open to the outside via small pores known as spiracles. These spiracles are not designed to be submerged, and water can easily enter and block their respiratory passages, leading to suffocation. Unlike some aquatic insects, house centipedes lack mechanisms to seal their spiracles to prevent water intrusion.
Their numerous long legs, while excellent for rapid movement across land surfaces, are not adapted for propulsion in water. These legs are slender and designed for gripping and running. While some centipede species, like certain Scolopendra, can undulate their bodies to swim, house centipedes do not exhibit this specialized aquatic locomotion. Their physical adaptations are geared towards terrestrial hunting and evasion, not an aquatic lifestyle.
Where House Centipedes Thrive
House centipedes prefer cool, dark, and damp environments, which provide the necessary humidity to prevent desiccation, and are often found outdoors under rocks, logs, leaf piles, and in compost. Indoors, they commonly inhabit basements, bathrooms, crawl spaces, and other areas with elevated moisture levels. These locations offer both the humidity they require and access to their prey, such as insects and spiders. House centipedes are nocturnal hunters, typically hiding during the day and emerging at night to seek food. While they seek out moisture, this is for hydration and to maintain their body’s moisture balance, not for swimming.