Diggers moved onto area of fiercely-debated green belt land last week without any prior warning, leaving residents shocked.
Six foot by six foot holes were dug up in the Redmoss Farm area of Milton of Campsie in order for the developer to carry out site investigations, expected to take five days.
Locals are worried about accidents due to an apparent lack of signage alerting dog walkers and other land users.
Bellway Homes own the land and hope to build 80 houses on the site, although no plans have been submitted yet.
Secretary of Milton of Campsie Greenbelt Preservation, Alan Harris, said: “This is a highly charged situation which could explode at any moment. At the very least they ought to stick up a sign, the machines are dangerous.
“Local people are rightly concerned from a safety point of view. It’s very provocative.”
A campaign to save the green belt is currently ongoing and the fate of the site is out for public consultation in the proposed Local Development Plan.
Sasha O’Neil, of Bellway Homes, said: “We have to do this prior to the planning process to find out if the ground is suitable.
“We’re certainly not looking to do anything untoward. It’s a normal part of the planning process. Johnson Poole and Bloomer are the contractors working on our behalf and we’re very confident that works will be adequately protected. They have a good track record of health and safety.”