Peccaries are known to play a significant role in shaping the diversity of habitats and structure of plants in rain forests. However, very little is known about their roles in regulating animal populations. I review the ways peccaries increase disturbance, create habitat diversity, provide resources, act as predators, and might otherwise directly and indirectly affect other animals. To determine effects of simulated peccary extirpation on the detrital food web, I examined the hypotheses that a reduction of peccary density on fenced exclusion plots would cause changes in the amount and quality of leaf litter as habitat for leaf litter reptiles and amphibians. I found that compared to open controls, exclusions had significantly deeper litter and more rapid cellulose decomposition. Exclusions were thus expected to provide more habitat and prey for litter amphibians and reptiles than control plots, but, paradoxically, encounters of reptiles and amphibians were greater on controls.