The answer to 'wasp trails' is that wasp trails are a sign of an active wasp nest nearby. Wasps leave pheromone trails to mark the path from their nest to food sources, which can lead them right to your home. Common causes include having ripe fruit, pet food, or other attractants around your property.
Symptoms of wasp trails include seeing a steady stream of wasps flying in a straight line, often high up on your home's exterior. This indicates there is likely a nest in your attic, eaves, or another hidden location. While wasps are generally not aggressive unless provoked, their trails can be a nuisance and pose a stinging risk, especially for those with allergies. The best solution is to locate and remove the nest, which is best handled by a professional pest control technician.