If you are on the tidal flats on a quiet day, you can hear the corophium wallowing in the mud. They make a remarkable dry crackling sound. Corophium are very common inhabitants of the muddy flats. In the summer, their population can reach densities greater than 10,000 per square meter. They dig tunnels, from which they gather food with their long tentacles, consuming as much as 4000 diatoms per day. This amount of diatoms must be processed and therefore corophium eject wastes up to 1000 times a day.