crawls

The term crawls refers to several domains that describe creeping or traversing motion, and to related processes in sports and technology. In biomechanics and development, crawling refers to the early form of locomotion used by human infants and by many animals that move close to the ground. Infant crawling typically begins around six to ten months and involves either belly-first "commando" crawling or hands-and-knees locomotion, advancing by alternating arm and leg movements. Crawling serves as a transitional stage between reflexive movements and walking, and variations exist across individuals and cultures.

In swimming, the term crawl commonly denotes the front crawl, the fastest standard stroke in competitive swimming. It features an alternating arm pull with a flutter kick and coordinated breathing to the side. The stroke emphasizes forward propulsion and streamlining, and forms the basis for the freestyle events in most competitions.

In information technology, crawling describes the automatic retrieval of web pages by software called web crawlers or spiders. Crawlers traverse links across the internet to index content for search engines, collect data for researchers, or monitor sites. They operate under rules such as robots.txt, may respect rate limits, and can be assigned crawl budgets to limit effort on large sites.

Crawling also appears in architecture and construction as a descriptor for crawl spaces—narrow, accessible areas beneath buildings used for services and inspection. These spaces require moisture control and ventilation due to restricted airflow.

Overall, crawls cover a range of creeping and traversal activities across living bodies, sport, and automated systems, illustrating how a common physical idea—moving close to a surface—has found diverse technical applications.