Atomic force microscopy: A powerful tool for studying bacterial swarming motility

► We applied AFM imaging in bacterial swarming motility studies. ► We focused on the Gram-positive bacterium Bacillus thuringiensis. ► AFM could discriminate between swarming and non-swarming cells. ► AFM could quantify cell shape and flagella expression. ► AFM demonstrated the key influence of agar softness and colony localization.