One of my favorite things about going to the beach every year is taking long, early-morning walks along the water before the hustle and bustle of the crowds begin. It’s my time to take in the wonders of our ocean and breathe in the salty air. As I drag my feet along the sand and across those tiny little holes that are seemingly everywhere—which, to me, give the appearance of beach polka dots—I’ve always wondered: What exactly is living in those little holes on the beach? 

Ghost Crabs

The holes that ghost crabs create can range from a few inches to just half an inch in diameter and serve as protective tunnels. Ghost crabs spend most of their days in their holes and come out at night to scavenge for food. They wet their gills by periodically taking water from moist sand or running to the shoreline for a quick splash in the waves. Time is of the essence, however, as they can drown if they stay in the water for too long. They have strong claws and speedy legs and are around the same color as the dry sand—when they move quickly, they can look like tiny ghosts dashing around the beach. 

Ghost Shrimp

Ghost shrimp holes are often distinguishable by the surrounding small fecal pellets that resemble ice cream sprinkles. (I know, apologies for the visual.) These nearly translucent creatures have legs and claws at the fronts of their bodies, but their backs are soft and mushy, making it difficult to defend themselves against predators or drying out from the sun. To protect themselves, ghost shrimp burrow deep into the sand, about four feet down. They use their legs to pull in ocean water so they can feast on plankton, then push or flick the water back up and out of the hole to keep their burrow clean—hence the surrounding “sprinkles.”

Sandworms/Lugworms

Sandworms or lugworms create U-shaped homes down in the sand with two separate openings at the surface—and once their burrows are created, they rarely leave. They can grow to be between three to 12 inches in length, so there’s a bit of digging required for each burrow. One opening serves as the feeding “pit” where they ingest food particles like decayed organic matter, along with sand sediment. The other opening is for ejecting excrement. Like their (what I presume to be) friends, the ghost shrimp, you can discern between the holes due to the surroundings—in the sandworms’ case, a coiled cast of sand.

Sand Dollars

If you notice two, three or more holes very close together, be gentle! Sand dollars often bury themselves just beneath the wet sand. To do so, they use the holes on their backs to move water and sand through and plunge themselves through the surface, and the keyhole shapes are what we see from above. Sand dollars have jaws with five sections of what are essentially small teeth, which can easily grind up plankton and other food. They need water to survive, so like other ocean creatures, removing them from their homes threatens their survival.

Just as there is certainly marine life undiscovered by humans deep beneath the sea, there are surely countless critters living beneath our sand—and joining me on my morning walks. What we do know, however, is that our ocean and beaches are really special places full of incredible creatures. Take a deep dive into our Ocean Conservancy Wildlife Library to learn more about some of our favorites.