bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.64898/2026.10.23.761437

Camus: a video-based framework for continuous behavioral monitoring in the mouse home-cage

Mehta, T.·Angulo, N.·Lu, A.·Staten-Lusty, S.·Im, V.·Palkar, R.·Nadazideh, C.·Steward, G.·Nakhjiri, C.·Guo, Y.·Kimchi, E. Y.
View original source ↗Export metadata ↓

Abstract

Home-cage activity is a window into the spontaneous behavioral repertoire of mice. These behaviors are organized across the circadian cycle, and disruptions in their duration, frequency, or organization may provide sensitive measures of neurological or psychiatric dysfunction. While continuous monitoring can help track the dynamics of spontaneous behavior, video recording in conventional laboratory cages is limited by compact cage geometry, opaque cage tops, and obstructed views of animals, food, and water. We therefore developed Camus, a Camera for home-cage recordings of Mus musculus mice. Camus integrates off-the-shelf USB cameras with infrared illumination and custom 3D-printed components for access to food and water without obstructed views. The modular design pairs continuous video acquisition with a manually validated computer-vision model to quantify locomotion, feeding, drinking, and nesting-related behavior across multiday recordings. A single desktop computer can record as many as 20 cages in parallel at an incremental cost of approximately $250 per cage, recording more than 99% of expected frames at 640x360-pixel resolution and 30 frames per second. Camus captured circadian structure in locomotion, feeding, and drinking. Camus also captured nest-building and sex-specific differences in nest dynamics. Using Camus with transgenic 5xFAD mice overexpressing amyloid revealed selective, age-progressive deficits in nesting behavior. Camus provides a scalable, open-source platform that combines accessible hardware, automated video monitoring, and machine-learning based analysis for continuous and potentially longitudinal behavioral phenotyping.

Explore related subjects

animal behavior and cognitionPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Mehta, T., Angulo, N., Lu, A., Staten-Lusty, S., Im, V., Palkar, R., Nadazideh, C., Steward, G., Nakhjiri, C., Guo, Y., Kimchi, E. Y.. 2026-10-24. Camus: a video-based framework for continuous behavioral monitoring in the mouse home-cage. https://doi.org/10.64898/2026.10.23.761437

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

KEEP EXPLORING

Related preprints

bioRxiv2026

Characterizing risky play-like behaviour in juvenile versus young adult rats

Play is an evolutionarily conserved behaviour that contributes to healthy behavioural and neural development. While animal play is traditionally categorized as locomotor, object, or social play, developmental research in children has highlighted the importance of risky play, defined as voluntary engagement with uncertainty and manageable physical risk. Whether similar forms of behaviour occur in non-human animals remains largely unexplored. The present study aimed to establish an ethological framework for identifying and quantifying risky play-like behaviour in rats. Juvenile and young adult male Lister Hooded rats were repeatedly exposed to a custom-designed environment containing elevated and unstable structures that provided opportunities for climbing, balancing, hanging, jumping and social interaction. Behaviour was quantified using two complementary ethograms: a location-based ethogram describing the animal's position within the apparatus and a risky event ethogram capturing selected behaviours associated with physical challenge. By comparing the behaviour of animals during the natural peak of play behaviour with animals beyond this developmental period, we aimed to evaluate whether engagement with elevated and unstable environments reflects play-related processes rather than environmental complexity alone. This study provides a behavioural framework for investigating risky play-like behaviour in rodents and establishes a foundation for future studies examining its developmental and neurobiological significance.

animal behavior and cognition↗
bioRxiv2026

Toward welfare indicators: leg condition and aversive stimuli modulate defensive behavior in Opilones

The history of invertebrate use in research and their growing use in managed settings highlight the need for validated behavioral indicators of welfare, yet these remain poorly understood across taxa. The arachnid group Opiliones (harvestmen or daddy long-legs) is an ideal group for identifying welfare indicators, given their well-characterized defensive behavior, including the common strategy of leg autotomy. The goal of this project was to identify candidate behavioral welfare indicators for Prionostemma sp. 1 in the Neotropical rainforest. We brought field-collected individuals with different leg conditions to the lab and briefly exposed them to an aversive stimulus (a gentle squeeze and release) paired with an assigned substrate (either rock or sand). A rewarding stimulus (food) was provided on the alternate substrate. We found no evidence of preference for roosting on the substrate associated with the rewarding stimulus, nor avoidance of the substrate associated with the aversive stimulus. Thus, evidence for associative learning was not supported. Additionally, substrate use did not differ based on leg condition (intact, missing 1-2 legs, or missing sensory legs). After an aversive stimulus, fleeing was consistently the most common response throughout 5 days. In contrast, the frequency of bobbing increased while the frequency of escaping decreased over trials. Individuals with all legs tended to escape more often than those missing legs, but neither the number nor the type of missing legs substantially improved predictions of behavioral responses. Overall, fleeing and bobbing may serve as behavioral indicators of negative welfare states, whereas the observed absence of exploratory tapping following the aversive stimulus suggests that this behavior may indicate neutral or positive welfare states. As one of the first investigations of welfare indicators in wild arachnids, this study provides novel insights into how defensive behaviors and physical condition may inform assessments of invertebrate welfare, laying the groundwork for future validation of behavioral indicators.

animal behavior and cognition↗
bioRxiv2026

Sensitive period for song learning outlasts parent-offspring cohesion in wild zebra finches

Communication is central to social behaviour, with vocalisations playing a crucial role in many species. In some species, vocalisations are learned, with songbirds being key to understanding vocal learning. The Australian zebra finch (Taeniopygia castanotis) is the most studied model organism for vocal learning. In captivity, juveniles are typically housed with their father, where males learn their father song and females develop a preference for that song. In nature, however, the social structure of zebra finches is more dynamic across space and time. To identify the natural social conditions during song learning, we followed zebra finch families across their early life in the wild using automated radio-tracking. The distance between juveniles and their parents increased post-fledging and became similar to the distance between juveniles and unrelated adults by the second half of the song learning period. These findings indicate a highly dynamic social environment during the song learning period and suggest that juvenile males could learn from many tutors and that females may develop broader song preferences. Thus, studies based on one-tutor paradigms should be interpreted carefully with respect to functional implications and highlight that future vocal learning studies could better reflect the social conditions under which song develops.

animal behavior and cognition↗