The scientists studied the types of small animals living in the mud and sand of Hampton Roads, Virginia. They found that different species prefer different types of habitats, like mud or sand. Some species are found all over, while others are only in certain places or times of year. The diversity of species was highest in sandy areas and lowest in muddy areas. The number of species increased from February to August in muddy areas, but peaked in May in sandy areas. This shows that the types of animals living in the mud and sand change depending on the location and time of year.