One of the most common parasites of eastern woodrats are botfly larvae. Adult botflies lay their eggs outside the entrance of the woodrat’s den. They then attach themselves to the woodrat’s fur when it passes through entrance. Once the eggs hatch, the botfly larvae penetrate the skin and lodge in the woodrat’s neck, chest, and abdomen until pupation. The resulting cyst can be 15 mm in diameter but does not seem to cause any obvious discomfort. Botflies infest approximately 16% of the eastern woodrat population.