Sand Hoppers in Wood?

Sand Hoppers in Wood?

Observation - Sand Hoppers in Wood?. Description: I have recently made a wooden installation from old scaffold boards. They were outside before construction and have been indoors for around 6 weeks. Recently some small, sand hopper looking bugs (10-12mm and smaller) have started to come out of the crevic

I have recently made a wooden installation from old scaffold boards. They were outside before construction and have been indoors for around 6 weeks. Recently some small, sand hopper looking bugs (10-12mm and smaller) have started to come out of the crevices and seem to be dying. I am yet to see a live one but the dead ones are orangey brown in colour and very flea or shrimp like in shape. Is it likely to be sand hoppers? The boards were kept within 1/4 mile of the sea but have not been kept directly on the beach. And if it is, will they damage the wooden installation or cause harm as they are in a confined public space where food stuffs are present? Please could you advise as to identification and likely ongoing progression?