A comparative burrowing study was performed using two estuarine clams, Rangia cuneata (G. B. Sowerby I, 1831) and Polymesoda caroliniana (Bosc 1801). These studies were carried out using three types of sediment (sand, silt, and clay) removed from the clam's native environment and placed into separate tanks. The number of burrowing events, in which the animals actively burrowed into the sediment, and the duration of time over which these events occurred were recorded and analyzed. There was a significant effect of sediment type on the number of burrowing events, but not so much on the duration of events. Pairwise comparisons between sediment types revealed subtle differences regardless of species. From these results, we report that sediment type can significantly influence the burrowing behavior of sympatric clams, but in different ways; and note observations on how these species physically interact and alter the substrate when burrowing.