A pitfall trap is a simple device used in ecology and entomology to capture small animals, particularly insects and amphibians. It consists of a deep hole dug into the ground, often lined with a container to collect the trapped organisms. When animals fall into the pit, they cannot escape, allowing researchers to study their populations and behaviors. These traps are commonly used in field studies to monitor biodiversity and assess the health of ecosystems. By analyzing the captured species, scientists can gain insights into the local environment and the effects of factors like climate change and habitat destruction on wildlife populations.