Why you should never buy a rat alone.
In this blog, I have linked many articles showing the negative effects of social isolation on rats along with an explanation to some of the articles as to why baby rats should never be alone and why they should always be purchased in pairs.
http://www.sciencedirect.com/science/article/pii/0166432896001817 In this study, rats that were isolated from weaning for 6 weeks (just 6 weeks) showed aggressive and avoidance behaviors. These aggressions were displayed as biting and boxing other rats when introduced. Even when given diazepam preemptively, isolated reared rats still showed aggressive behavior even though it was reduced but their avoidance behaviors were not changed even on diazepam.
Keeping the baby rats alone causes them to not be able to easily introduce to another rat to them and can make for very long intros. http://www.sciencedirect.com/science/article/pii/S0006899303035972 This study is very eye opening, lone rats show a reduction of long-term potentiation (LTP), which is the strength of their synaptic response following stimuli. This affects things such as memory. A decrease in LTP causes many neurological diseases including depression, Parkinson, epilepsy and neuropathic pain. Keeping baby rats alone causes severe neurological changes and pain. They can be in physical pain by being alone during those essential weeks after weaning. http://www.sciencedirect.com/science/article/pii/S0149763408000353 This study shows that rats reared in isolation or having mom removed to early affects the brains development and adult behavior may contribute to depression and schizophrenia. “Rearing rat pups from weaning in isolation, to prevent social contact with conspecifics, produces reproducible, long-term changes including; neophobia,” the fear of new things, experiences, change, “impaired sensorimotor gating,” the ability to filter out redundant or unnecessary stimuli, resulting in overly anxious animals,” “aggression, cognitive rigidity,” the difficulty in changing mental sets, “reduced prefrontal cortical volume” literally reducing the size of the brain! “and decreased cortical and hippocampal synaptic plasticity.” The hippocampus is responsible for emotions memory and the central nervous system of the brain and rats living alone decreases the ability for them to be able to properly respond to stimuli. Both early weaning and being kept in isolation makes rats less smart, more anxious and unable to fully analyze and response to a situation creating a rat that may react abnormally. http://www.sciencedirect.com/science/article/pii/S0028390810000080 “Although physical isolation of rats is known to cause anxiety- and depression-like symptoms, the underlying mechanisms are not fully understood.” This article starts off with the very clear statement that rats housed alone are not mentally healthy rats. However, this is the first article that does state that reintroduction after this period can completely reverse the effects of the socialization. Something to remember here is that the rats are still young, 6 weeks after weaning age in a lab is 9-10 weeks. These rats brains are more malleable. And just because it can be reversed, keeping a lone rat and causing that amount of stress even if it can be reversed is not humane. There are many many more articles about social isolation in rats and social isolation is used to simulate anxious and depressed like behaviors for studies in facilities.
Buying a baby rat by itself is never ever a good idea. Social isolation is detrimental to your rat’s health. A baby rat needs rat friends like it needs food, water and a clean cage. It’s not an option.
More articles on social isolation in rats.
http://www.sciencedirect.com/science/article/pii/S0091305705003928 http://onlinelibrary.wiley.com/doi/10.1002/syn.10133/full http://www.sciencedirect.com/science/article/pii/S0166432803003796 https://link.springer.com/article/10.1007/BF02244105
