Whilst in the desert near Tayma, central Saudi Arabia, I came across hundreds of bright red-orange caterpillars on the sand. On asking some experts, they came to the conclusion they were a processionary moth Thaumetopoea caterpillar. They are a human irritant because of their venomous hairs, which can cause skin irritation. The exact species involved has not been ascertained. This is the first time I have seen these caterpillars in Saudi Arabia and they certainly made a spectacular sight.
