Laboratory rats might live better lives if they had cages that let them stand up, climb and romp about, according to researchers who gathered lessons on the animalsâ behaviour from pet rat owners.
at the University of Bristol in the UK turned to private ownersâ expertise to learn how to improve ratsâ living environments and recognise possible indicators of their well-being.
âAllowing rats to express natural behaviours is really, really important for their welfare and for better science,â says Neville.
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As a scientist who has 18 former lab rats now living as pets in her home, Neville says pet rat owners have untapped potential for learning about the rodentsâ behaviour.
âIâve taken rats home from every study that Iâve completed so far, and I have learned so much just by having them at home, watching them and seeing behaviours that I had never seen in the lab before,â she says.
Neville and her colleagues gathered data from an online survey completed by 677 owners in the UK with a total of 3893 pet rats.
The owners reported that younger rats in particular like to play, climb and stand upright â called ârearingâ in rats. In general, rats like to dig into their bedding, hoard food, nest and bound across the cage floor in âdolphin-likeâ leaps, says Neville.
However, most laboratory cages would prevent such natural behaviours, she says. Measuring only 48 centimetres long and 38 cm wide with a height of 21 cm, standard lab rat cages restrict activities like bounding, climbing and standing up. As adults, rats can rear to a height of around 30 cm.
Bigger laboratory cages with deep bedding for digging could offer rats better welfare, says Neville. If that isnât feasible, laboratories could install âplaypensâ â large, tall cages enriched with toys and bedding where rats could spend a few hours a day with other rats.
The survey results also led to the first ever scientific description of âbogglingâ in rats: rapidly protruding and retracting the eyes. The behaviour often occurs at the same time as a tooth-grinding behaviour known as bruxing. Owners reported that their rats boggled and bruxed when they were content, so researchers could consider looking for these behaviours as a measure of good welfare, says Neville.
When pet rats could smell a potential predator, like the family cat, they were much less likely to dig, bound, pin and brux, owners reported. So an absence of these behaviours in lab rats might suggest the rats are feeling stressed, says Neville.
The findings are âreally interestingâ, especially since this is one of the few studies to ever explore pet rat behaviour, says at Purdue University in West Lafayette, Indiana. However, she cautions against assuming any cause-and-effect relationship between the pet ratsâ behaviours and their well-being.
âAre these [owner-observed] behaviours highly valued to rats?â says LaFollette. âAnd is that something thatâs going to improve their welfare?â Follow-up studies in controlled experimental conditions could help answer those questions.
Until then, any practical applications are limited, she says. âI donât think you can take this paper and then say, well, because the pet rats are doing this, we need to give it to laboratory rats.â
Even so, improving welfare in laboratory animals is critical, says Neville. Allowing them to express their natural behaviours is not only a good ethical choice, but also an important element of sound science. âHappy animals lead to good science,â she says.
Applied Animal Behaviour Science
