Patterned postmortem ant abrasions outlining clothing and body position after death

Highlights

• Typical post mortem ant activity causes irregular parchmented lesions in the skin.

• Two types of lesions caused by ants provide a visual record of clothing and position.

• Areas of abraded skin with well-defined edges marked clothing.

• Circular abraded injuries outline the points of contact of the body.

• Not all insect predation on bodies obscures information.

Abstract

Analysis of a series of cases where post mortem lesions had been caused by ant activity demonstrated two types of specific lesions, the first associated with clothing, and the second with the position of the body of the decedent. The first type of injury consisted of areas of abraded parchmented skin with well-defined straight edges that marked the perimeter of clothing. The second lesion consisted of circular abraded injuries that outlined the junction between the body and the surface that it was resting on, essentially tracing the outline of the point of contact. In both situations ants had been unable to gain access to skin beneath elasticized clothing or parts of the body pressed against the floor or ground. This had resulted in a visual record of the edge of clothing and the position of parts of the body after death. This information may be important if clothing has been removed prior to autopsy or if lividity is minimal. These unique lesions also show that not all insect predation on bodies obscures information.

Introduction

Post mortem predation by a wide range of animal and insect species can create considerable problems at the time of autopsy when attempting to differentiate post from antemortem injuries.¹ Different species are associated with different lesions that are influenced by the size of the marauding animal, the nature of the feeding process, and the environment of the body and animal. For example, terrestrial carnivores such as dogs and foxes will often strip soft tissues from the face and head and eventually eat their way into the chest cavity.² Bears focus more on the axial skeleton and remove vertebrae, while aquatic sea lice burrow under the skin removing large amounts of subcutaneous soft tissues.³

Insects tend to colonize bodies in an orderly sequence such that entomologists are able to make an estimate of the time of death based on the species present and the degree of decomposition. Ants are very early colonizers of corpses and feed off keratin in eyelashes, eyebrows and the superficial skin. While the classical serpiginous, parchmented lesions are well-recognized,4, 5, 6 the following cases demonstrate particular patterned lesions that give clues as to the clothing worn and the position of the body during predation.