This is my entry for the #monomad challenge.
If you don't try to pay attention to them, they are there. Their tiny bodies with a very similar color to the color of sand make it easy for them not to get your attention. You walk on the warm sand of the beach, and there they are. But if you pay attention to them, especially trying to approach them, they immediately know your intentions. They will run immediately.
Although very small, their legs will make an incredible speed when running (can reach two meters per second), in addition, they can rotate in any direction with ease.
They would gallop on the warm sand of the beach in the late afternoon, and then immediately enter the holes they had dug, or most of the time, they would dash into the sea, and disappear beneath the waves.
When you leave them and show an indifferent attitude towards them, they come back there, digging holes or going out to scavenge carrion and small animals.
They are crabs in the family Ocypodidae, known as Ghost crabs or sand crabs.
Their presence there actually adds to the pleasure of being on the beach. Even if you are on a quiet and secluded beach, you will not feel lonely. They, the beautiful little ghosts will accompany you there! And here are their black-and-white pictures.