The answer to 'retaining wall pests' is that common pests that can infest retaining walls include termites, ants, and rodents. These pests can burrow into the soil and wood components of the wall, causing structural damage over time. Symptoms may include visible damage, mud tubes, or droppings around the wall.
For minor infestations, homeowners may be able to address the issue through DIY pest control methods like applying insecticides or sealing entry points. However, for more severe or recurring problems, it's best to call in a professional landscaping or pest control specialist to properly identify and treat the issue. They can assess the extent of the damage and recommend the most effective solution to protect your retaining wall.