Artifacts Caused by Leaf‐Cutting Ants of the Genus Atta (Hymenoptera: Formicidae): Postmortem Bite Injuries and the Tearing of Clothes

Abstract

Ants are one of the first insects to find an exposed cadaver and can be present during all stages of decomposition. Although these organisms are not commonly used in postmortem interval estimates, they are to be taken into account on criminal investigations involving human corpses, since they can leave bite marks that can be mistaken for antemortem or perimortem injuries, which could be misleading when ascertaining the occurrence of abuse or physical altercation during a crime. A few studies report the action of ants on human cadavers and even though leaf-cutting ants of the genus Atta are frequently encountered in succession studies that use animal carcasses, there are no records of these fungus-growing species on human corpses. Atta is a genus restricted to the New World, ranging from northern Argentina to southern United States and acts as one of the most conspicuous neotropical herbivores. In this study, we report three cases of violent death that illustrate the impact of ants, especially those of the genus Atta, in a forensic setting. We compare the patterns displayed by postmortem bite injuries caused by leaf-cutter ants and other common species with less robust mandibles. We also present the capability of Atta ants to create artifacts by cutting victim's clothes in a crime scene, contributing to the knowledge of ant-mediated confounding factors in crime scene investigation.

Seasonal distribution of Calliphoridae and Mesenbrinellidae (Diptera) associated with the decomposition of a clothed animal model in a forest reserve in the Central Amazon

“…Thus, the activity of this insect should not be neglected in forensic analyses. In addition, cuts made by Hymenoptera (Formicidae) were also observed in the clothing, who were probably attracted by the presence of Diptera larvae in the region, this behavior also was observed by Somavilla et al (2019) and by Souza et al (2020), the latter for human cadavers. Even so, both works warn of possible interpretation errors that may occur due to the mistaken analysis of these vestiges.…”

Ant bite artefacts: A series of cases reported over a year

“…Ants may also impact the progress of decomposition as they tend to dominate the carcass by recruiting a large number of worker ants and prey on dipterian eggs, larvae and adults, thus interfering with colonization by necrophagus flies. 9 Byard, in their paper, presented a case report in which postmortem seepage of blood was conclusively attributed to ants who had removed superficial layers of skin in an area of dependent lividity. 10 The findings in our case were similar to such postmortem seepage baffling the relatives and the police alike.…”

Qualitative Analyses of Textile Damage (Cuts and Tears) Applied to Fabrics Exposed to the Decomposition of Carcasses and Associated Insect Activity in an Austral Summer

“…When the remains reach the advanced decay and the dry stages, insect species such as larder beetles, which are attracted to hair, bones, dry skin, and clothing, become more predominant [18]; these insects generally leave clear traces of their feeding action on fabrics [19][20][21][22]. Besides acting on pre-existing textile damage, the activity of carrion insects on clothed remains has been reported to produce de novo damage or tear-like artifacts, and to be the cause of clothing disarray, which may mislead the overall reconstruction of the events that may have occurred during a criminal event [23][24][25][26]. As a result of decomposition and insect activity, the outcome of an investigation requiring the identification of a weapon based on the damage produced on the clothing of a victim can be compromised [27,28].…”