The Construction Bot can build basic Tech 1 structures, and is the cheapest construction unit.

Use multiple on a single structure to increase build power.

It's quite slow and weak, so try to escort it with a few Pawns when expanding.

Each constructor also slightly increases energy and metal storage capacity, and produces a small amount of energy. This helps scale your economy just by having them alive, compared to Construction Turrets that don't increase storage or produce energy.