  This paper presents a novel swarm robotics application of chemotaxis
behaviour observed in microorganisms. This approach was used to cause
exploration robots to return to a work area around the swarm's nest within a
boundless environment. We investigate the performance of our algorithm through
extensive simulation studies and hardware validation. Results show that the
chemotaxis approach is effective for keeping the swarm close to both stationary
and moving nests. Performance comparison of these results with the unrealistic
case where a boundary wall was used to keep the swarm within a target search
area showed that our chemotaxis approach produced competitive results.
