I am interested in bacteria swimming and sensing. Bacteria can actively move around in their environment, swimming toward favorable conditions and away from unfavorable regions. In a homogeneous environment, certain motile bacteria preform a random walk. In a inhomogeneous environment, with gradients of chemicals and/or temperature, cells bias the random walk toward better conditions. Currently we are studying the response of Escherichia coli to impulsive exposure to both chemical attractants (certain amino acids) and temperature perturbations.