Swing marks made along a beam under floor joists generally indicate the presence of which type of rodent?

Swing marks made along a beam under floor joists generally indicate the presence of which type of rodent?

• A. House mouse.
• B. Norway rat.
• C. Fruit rat.
• D. Roof rat.

Answer: (D)

The way rodents move and where they prefer to travel inside a structure determines the signs you see. Roof rats are climbers that use elevated pathways—attics, ceilings, and beams under floor joists—as highways. When they move along these overhead supports, their bodies and tails brush the wood, leaving marks often described as swing marks. This overhead, arboreal pattern fits roof rats much better than other common rodents, which tend to stay lower—house mice along walls and low edges, or Norway rats on the ground levels or in basements. The swing marks on a beam under floor joists are a telltale sign of roof rats.

The way rodents move and where they prefer to travel inside a structure determines the signs you see. Roof rats are climbers that use elevated pathways—attics, ceilings, and beams under floor joists—as highways. When they move along these overhead supports, their bodies and tails brush the wood, leaving marks often described as swing marks. This overhead, arboreal pattern fits roof rats much better than other common rodents, which tend to stay lower—house mice along walls and low edges, or Norway rats on the ground levels or in basements. The swing marks on a beam under floor joists are a telltale sign of roof rats.