Timothy Mitchell's book Rule of Experts has a well-known chapter that makes a semi-serious argument that mosquitoes have to be understood as agents in the history of mosquito-borne diseases, riparian agriculture, etc. In this, Mitchell is working a bit off an idea that is associated with the critical theorist of science Bruno Latour, referred to as actor-network theory, which also tries to understand environments, objects, animals and institutions as "agents" in an active sense.

​

There is also a considerable body of historical work at this point on relationships between animals (both domesticated and wild) and human communities that tries to understand those relationships as ones that humans did not control in some masterful sense. A good deal of this examines the shift in cultural and intellectual thought in early modern Europe from everyday or folkloric frameworks that saw animals as possessing responsibility and agency for their actions and saw animals as being subject to human punishment. Robert Darnton's The Great Cat Massacre discusses one famous instance of this; Patrick Phillips' Medieval Animal Trials mentions many such examples. Jon T. Coleman's Vicious brings some of this perspective into a discussion of why early European settlers in North America killed wolves in such large numbers.

In fact, many human societies have seen animals as possessing some form of will, intention or agency, whether quite literally ascribed to actual, real animals, or through mythological or religious visions. Many spiritual practices referred to as "animism" have seen agency or intentionality as widely distributed not just through animals but the entire natural world, including plants, rocks, water and other natural systems.

So this is at least a widely distributed idea in human history, including in the present day. What are the obstacles to seeing animals as agents? Fundamentally, the problem here is the distinctive modern, Enlightenment-inspired understanding of agency that is so powerful in contemporary political and legal systems. "Agency" is itself a pretty messy and frequently underdefined or underspecified term. It can be a polite synonym for the modern vision of individuals as conscious, self-willed, self-ruling, autonomous actors who are responsible for all of their actions and who rationally decide to do whatever it is that they do. It can mean something far vaguer that implies both action and some conception of intention to act but doesn't necessarily rest on such a specific conception of mind, consciousness and individuality. Sometimes when we talk about agency, we also are talking about the conditions that allow (or prohibit) human action--so we can speak or less or more agency, or "giving back" someone their agency, or complain of situations that restrict or repress agency.

​

For this reason, to talk about animals having agency is inextricably tied to implying that animals not only act but intend to act; that they are in some sense or another aware of their actions. Here you slip from r/AskHistorians to r/AskPhilosophy in a substantial way, because I don't think any historian is ever going to provide unimpeachable evidence of the self-conscious intent of an animal to act in a particular fashion, whether that's a household dog, a mosquito, or a medieval pig that has destroyed the grain stocks of a peasant village. I think it is within the purview of historians to suggest that animals act in ways that are responsive to human action, that those actions are unpredicted and uncontrolled by human action, and thus are in some sense autonomous "agents" in the unfolding of change over time, independently of human agency. If you have an interest in the next step, which is appraising animals as intentional or conscious or self-aware, you have to jump to a slightly different epistemological and methodological conversation.