Why are repellents considered a temporary solution to vertebrate pest problems?

Repellents are considered a temporary solution to vertebrate pest problems primarily because they need to be reapplied after rainfall or snowfall events. When precipitation occurs, it can wash away or dilute the repellent, reducing its effectiveness. This means that even if a repellent successfully deters pests initially, environmental factors like rain or snow will necessitate reapplication to maintain its effectiveness. Therefore, while repellents can provide a short-term solution to keep pests at bay, their reliance on consistent application limits their long-term effectiveness as a pest management strategy.