This article presents an algorithm for the automatic detection of circular shapes from complicated and noisy images. The algorithm is based on a recently developed swarm-intelligence technique, well known as the Bacterial Foraging Optimization (BFO). A new fuzzy objective function has been derived for the edge map of a given image. Minimization of this function with an adaptive version of the BFO algorithm leads to the automatic detection of circles on the image. Categories and Subject Descriptors I.2.8 [Artificial Intelligence]: Problem Solving, Control Methods,