If the 'wood' shrimp is doing most of his feeding by picking at the substrate, he is probably very, very hungry. I would think this is an Atya gabonensis shrimp. Being filter feeders, they need a water current to feed in and a place to perch so they can sit in the water current. Mine sit on a sponge tied to the side wall in the pump's flow path, also on wood and plants in the flow path. I feed them microworms at least once a week, cultured green water and Golden Pearls in the 5-50 micron size, all of which they can filter out of water with their fans. Sometimes I have used powdered fry food, but it does not sink very well, and thus is not as much use to them.
I usually turn the filter off for a half hour when I feed them, about 3 times a week, and leave the pump running to circulate the food. I have had very good success at keeping them alive and growing this way. If the tank is very mature, they can find enough to eat in the water column for some of the time, but if I don't supplement their diet, they don't live very long. Learned this the hard way, of course.
Charming shrimp, I currently have 3 different species of fan shrimp. Gabonensis, aka Vampire shrimp, Atyopsis moluccensis, Wood or Bamboo shrimp, and Atyopsis spinipes, miniature fan shrimp. I used to have a variant of this last species called Golden Fan shrimp, same species but body colour identical to Bamboo shrimp, to the point they appear to be juvenile bamboos. But they never get grow larger than about 1.25 inches.
Your shrimp really needs a perching spot where he can sit in the water current and filter feed, which is very much what they prefer. That's why they have those 'fans' on their feet. If I see mine picking at the bottom, I increase the number of feedings I give them until they stop doing it.