Name a common indicator that a pest is present.

Visible damage to plants, such as holes or discoloration in leaves, is a common indicator that a pest is present because it directly results from the feeding or activity of the pest on the plant. When pests infest a plant, they may chew through leaves, create holes, or cause nutrient deficiencies that lead to discoloration. This damage serves as a clear visual sign for farmers, gardeners, and agricultural professionals that action may be necessary to assess and manage the pest population.

The other options may not indicate the presence of pests clearly. For example, visible growth of plants may suggest they are healthy and thriving rather than infested, while pest-related smells can be subtle and not universally recognizable as a sign of pest presence. The presence of beneficial insects does not necessarily indicate pest presence on its own; instead, it often signifies a healthy ecosystem that can help control pest populations. Thus, visible damage to plants is a straightforward and observable indicator of pest activity.