bioRxiv Science⌕ Search

bioRxiv · 10.64898/2026.04.29.721812

Thinking outside of the box: Refining rat housing to improve welfare

Abstract

Standard rat housing may impede species-typical behaviors and impact rat welfare and research outcomes. This research investigated the effects of housing on behavioral and physiological outcomes of rats through the use of modified large animal cages for housing, and was conducted in two studies. Study A: 70 Sprague Dawley (SD) rats (34 males, 36 females; 5 wk old) were randomly assigned to standard polycarbonate shoebox cages (C: 733.9cm2) or modified stainless steel primate cages (T: 10,416cm2) for 18 days. In Study B: 48 SD rats (24 males, 24 females; 7.5 wk old) were held in T housing for 90 days to assess long term impacts. All rats received gentle handling for 15s 3x/week. Rats were assessed for body weight, anxiety-like behavior in an elevated plus maze, response during a voluntary human approach test, and overall home cage behavior, posture, and space usage. Data were analyzed using generalized linear mixed models, with sex and treatment as fixed effects, and cage as the random effect. The results of study A suggest that the modified large animal cages (T) had positive impacts on rat behavior and welfare. T rats were less anxious (P=0.038) and more active (P<0.0001) and explorative (P=0.0003) compared to C rats. In both groups, activity levels declined towards the end of the 18-day study period (P<0.0001). For study B, similar patterns were observed, with rats becoming more inactive (P<0.0001) over 90 days. However, rats spent significant time on elevated shelves in T housing, which increased throughout the study (P<0.0001), suggesting continued use of the resources the housing provided. In both studies, there were no differences in latency to approach humans (P>0.05), but T rats spent less time in contact with human handlers, suggesting differences in motivation to interact with humans that should be explored further.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

O'Malley, C., Paterson, E. A., Tambadou, H., Moreau, E., Ekundayo, O., Puoliväli, J., Collymore, C., Turner, P. V.. 2026-05-04. Thinking outside of the box: Refining rat housing to improve welfare. https://doi.org/10.64898/2026.04.29.721812

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

A comparison of female competitive traits: Female aggression peaks at nest building but female song spans multiple contexts in a temperate songbird

Female-female competition is increasingly recognized as a key driver of female ornamentation, including birdsong, which often functions in intrasexual competition. However, the specific resources females use elaborate traits to compete for remain unclear. In addition, few studies have simultaneously investigated the use of multiple competitive traits in females, despite growing independent interest in these traits (e.g., female song and aggression). We investigated the competitive contexts of female song, aggression and calling behavior in northern house wrens (Troglodytes aedon) to determine which resources females compete for across the breeding season. We simulated conspecific territorial intrusions using female song at three breeding stages representing different contexts: arrival (mate and territory acquisition), nest building (nest site and breeding status defense), and egg laying (brood defense). We tested whether female song and physical aggression varied as reproductive resources shifted across the breeding cycle. Females were significantly more aggressive during nest building, showing 5.8 times greater odds of a higher-intensity aggressive response during nest building compared to arrival. Female song output was similar across early stages but declined during egg laying, though this was not statistically significant after correction for multiple comparisons and individuals varied substantially in overall singing propensity. Non-song vocalizations varied by call type and breeding stage. Calls associated with aggression occurred most frequently during nest building, consistent with peak physical aggression responses. Together, these results identify nest building as the stage of highest female aggression, consistent with heightened competition over nest cavities and associated breeding status in this cavity-nesting species. In contrast, female song occurred across all stages and appears to function in multiple competitive contexts. This study provides evidence for context and mode-specific female signaling in a temperate songbird and highlights that females strategically use aggression, calls, and song to mediate social conflict across breeding contexts.

animal behavior and cognition↗

Tracking human foragers and their prey reveals adaptive predator-prey dynamics

Hunting for mobile prey is thought to have played a key role in hominin evolution, by providing high-quality nutrition that supported the development of the exceptionally large human brain. However, human-prey dynamics remain poorly understood because studies have not yet tracked human foragers and their prey simultaneously. Here, we employ high resolution tracking of groups of human foragers (ice-fishers) and their prey (fish shoals) to study human-prey dynamics. Our results show that foragers adaptively combined personal and social information in deciding where to forage and for how long, closely matching the prey distribution. Prey responded dynamically to human exploitation, showing increased attraction to fishing activity, alongside decreased biting probability. Furthermore, we found that foragers adaptively relied on memory, preferentially returning to areas with high prey presence, particularly when their current return rate was low. Our results show how human foragers overcome the challenges of extracting invisible, mobile and reactive prey by tightly tuning patch-selection, patch-leaving and patch-return decisions to the distribution and behaviour of their prey.

animal behavior and cognition↗

4-Dimensional Chess: Acoustic Localisation Reveals Nested Spatio-temporal Strategies in an Arboreal Communication Network

1. Adaptive behavioural strategies require animals to simultaneously navigate social and ecological domains across multiple spatial and temporal scales. Although drones and computer vision have recently transformed the study of wild animal societies, many nocturnal species and those occupying structurally complex habitats remain inaccessible to these approaches, limiting our understanding of behaviour in natural settings. 2. We aimed to determine how behavioural strategies are organised across nested spatial and temporal scales within a wild communication network. 3. We used three-dimensional acoustic localisation and source separation to track individual male Hyperolius sp. A, a nocturnal African reed frog, within a natural rainforest chorus and quantify patterns of site fidelity, movement, spatial organisation, and call-timing interactions. 4. Males exhibited significant site fidelity across nights, while chorus spatial structure varied with local caller density. Within nights, individuals followed a stereotyped behavioural sequence, descending from elevated arboreal refugia before settling into lower calling positions near breeding sites. At finer temporal scales, call-timing interactions varied according to both local competitor density and the proximity of neighbouring rivals. 5. These findings demonstrate that behavioural strategies emerge across nested spatial and temporal scales and that long-term spatial positioning, short-term movement decisions, and moment-to-moment signalling interactions are tightly linked within natural communication networks. More broadly, acoustic localisation provides a powerful framework for studying behaviour in species and habitats that remain difficult to observe using conventional approaches.

animal behavior and cognition↗