The cyprid larvae are designed for rapid swimming and bentic-habitat selection. The amount of reserves the cyprid stores limits the time available to search for an appropriate settlement site. As cyprid larvae grow older and the reserves are depleted, they are less specific in responding to settlement cues. Some studies have shown that higher settlement occurs lower in the intertidal presumably because that is the first available site with which the cyprids come into contact. At these seaward sites settlement and population density are high. This results in lower survivorship due to predation and lower growth rates. Cyprids that settle higher in the intertidal have lower population abundance and higher growth rates. Overall, the cyprids settle more in empty shells of adult barnacles except if a predator whelk or limpet has recently been at that shell. This suggests that cyprids are signaled to avoid settling in places recently visited by some mollusks by some substance in the mollusk’s mucous trail.
As the cyprids settle, they attach their heads to the chosen substrate with a cement formed by the antennae and morph into benthic juveniles. During this change, the appendages elongate to form cirri and the shell plates form. The juvenile grows into an adult which involves periodic molting. A juvenile B. glandula will grow to about half of its full size in its first year and three quarters its final size in the second year. During its life span of eight to ten years, B. glandula will reach a diameter of about 2 cm. The sessile adult community and the free-living larval communities are not totally isolated from each other because when settlement is high, the abundance of adult barnacles is also high.