Have you checked the engine in your tractor?

Birds are active building their nests, often in tractors or farm machinery motors, which poses a fire risk if it goes undetected.

Birds like to nest in any dry, accessible place in a tractor or other farm machinery including engines and exhausts which warm as the engine is started and operated. The birds use dry nesting materials which presents a significant fire risk as the dry material used to build the nests is highly combustible and easily ignited.

While all birds like to nest, tractors and machinery are most at risk from starlings which roost all year round . The birds are capable of building nests in under 30 minutes which can result in a nest being built in a warm tractor over lunch.