Feces

Definition

Solid or semi-solid waste material expelled from the digestive tract after food has been processed and indigestible residues concentrated; in arthropods, the composition and form vary markedly by diet and gut morphology. In insects, feces are often termed frass when referring specifically to larval excrement, which serves as a chemical signal, building material, or nutrient source in ecological webs.

Etymology

Latin faeces, plural of faex 'dregs, sediment'

Example

Lepidopteran larvae produce characteristic frass pellets whose size, shape, and location help field biologists identify species and assess population density; dung beetles (Scarabaeinae) rely on vertebrate feces as their primary food source and breeding substrate.

Synonyms

• excrement
• frass (insect-specific)
• droppings
• scat

Related Terms

• Frass
• Coprophagy
• guano
• Hindgut
• Malpighian tubules
• nutrient cycling
• scatology

Usage Notes

Frass is the preferred term for insect feces in entomological contexts, particularly for larvae; scat is used more broadly for mammalian and other vertebrate droppings in field ecology. Feces serve as important chemical communication sources (marking territory, signaling reproductive status) and nutrient hotspots in many arthropod communities. Form and composition vary with diet: carnivore feces differ markedly from herbivore or detritivore feces in nitrogen content, moisture, and physical structure.