How do ground-nesting ants protect themselves against pathogenic fungi?

• A. Antibiotic secretions produced from the metapleural glands on their thorax.
• B. Secretions from the mandibular glands used to deter predators.
• C. Secretions from dorsal glands used for waterproofing.
• D. Immune proteins produced in their gut.

Answer: (B)

Ground-nesting ants rely on chemical defenses that directly target pathogens in their environment. The metapleural glands, located on the thorax, secrete antibiotic and antifungal compounds that ants spread onto nest surfaces and themselves. This creates a chemical shield inside the nest, helping to suppress fungal growth and protect colony health—a clear example of social immunity in action.

Secretions from mandibular glands mainly serve defense against predators and are not the primary antifungal tool in the nest context. Dorsal gland secretions are associated with waterproofing and other functions, not the main antifungal defense. Immune proteins produced in the gut contribute to systemic immunity but do not provide the localized, nest-level antifungal protection that metapleural secretions offer.