Rats Are Us

A happy rat seen celebrating on April 4th

 

 

I.

 

Apparently, one of the things that neuroscientist Jaak Panksepp discovered in the late 1990s was that rats laugh and enjoy being tickled. Their laughter may not be what we would recognise as such - consisting as it does of ultrasonic chirps undetectable by the human ear - but laughter is what it is. 

 

We already knew that these intelligent and social animals liked to play, but we didn't know just how much they enjoyed it - literally squealing with joy and giggling with delight.    

 

 

II.

 

Apparently, rats also have a sense of time; possessing memories of past experiences and the ability to think ahead. This enables them to learn cognitively complex skills and, despite having brains much smaller than ours, there are some tasks in which they can outperform humans. 

 

Perhaps most surprising, however, is the fact that rats seem to feel empathy: "Since the 1950s and '60s, behavioural studies have consistently shown that rats are far from the egoistic, self-centred creatures that their popular image suggests." [1] 

 

In fact, rats do not wish to harm one another, feel distress when they witness other rats suffering, and will actively try to help rats that are trapped. In short: rats know what it is to care. But many people - including many scientists - simply don't want to face up to this fact, despite there having been a lot of (cruel) research since 2011 into rodent empathy [2].

 

Why? Because rats "are seen as cheap and disposable research tools" which are conveniently not covered by any pesky animal welfare legislation; "scientsts can legally do whatever they want to them" and hundreds of millions of rats are exploited and killed in labs around the world each year (so many in fact, that there is no official statistic). 

 

The justification is always the same: we wish to advance human knowledge and alleviate human suffering by discovering new drugs and therapies. 

 

But, of course, this ends justify the means defence is questionable from an ethical perspective when it comes to animal experimentation. Unless we are Nazis, we don't carry out horrific and deadly experiments on other human beings. And nor do we now inflict pain and suffering on fellow primates, such as chimps, having recently (and somewhat reluctantly) recognised them as thinking, feeling agents - just like us. 

 

But then, so are rats, it turns out; they too are sentient beings that love and laugh: "It is only our moral short-sightedness and relentless anthropocentrism that have prevented us from taking them into account."

 

 

Notes

 

[1] Kristin Andrews and Susana Monsó, 'Rats Are Us', Aeon (2 March 2020), ed. Sam Dresser. Click here. All quotes in the above post (and in note 2 below) are from this essay by Andrews and Monsó. 

[2] As Andrews and Monsó write:

 

"Scientists are now tinkering with rats' empathy in order to find ways of treating human psychopathologies. In some cases, rats are given treatments that temporarily disable their empathic capabilities, such as anxiolytics, paracetamol, heroin or electric shocks. In other cases, the harm is permanent. Rats are separated from their mothers at birth and raised in social isolation. In some studies, their amygdalae (the brain area responsible for emotion and affiliation) are permanently damaged. The explicit goal of this research is to create populations of mentally ill, traumatised, emotionally suffering rats." 

 

Fatal Attraction: On Cats, Rats, and Parasites

One live cat, one dead rat, and one plush toy parasite (available from giantmicrobes.com)

The Cat has caught five rats in five days: either she's a very skilled huntress, or the rodents who pass through my back garden are absolutely useless at keeping out of harm's way.

Alternatively, they could be infected with the parasite Toxoplasma gondii which seems to cause them to lose their innate fear of cats and, indeed, become amorously aroused when they smell cat urine, rather than run and hide.

This may sound like a joke, but it's true: researchers at Stanford University discovered that the brains of infected male rats show heightened activity in the region associated with sexual response and various emotional states. In other words, the parasite deliberately manipulates the romantic behaviour of male rats in order to increase the chance that they'll be eaten by a cat.

Why would it want to do that? Because T. gondii can only reproduce inside the cat's small intestine, so it's vital - if it wishes to complete its lifecycle - that it find a way into its definitive host's digestive system.

As one of the scientists in the research team said, it's very impressive: for there are not many protozoan organisms that can fuck with the heads of other (more complex) species in this manner. It might even be argued that T. gondii knows more about the neurobiology of fear and attraction and epigenetic remodelling than we do.

Afternote

Once T. gondii has reproduced inside the cat's gut, the parasites are excreted in faeces; which is how shit-eating rats become infected, though they can infect any warm-blooded animal, including human beings. In fact, it may interest readers to know that approximately 30-50 per cent of the world's human population is believed to be infected with T. gondii (in France, this figure rises to over 80 per cent).

Fortunately, for most people, infection causes no ill effects, but it can be fatal for those with compromised immune systems and there are also recent studies showing that there may be a possible link with schizophrenia. So, perhaps these parasites are playing with our brains too, which, actually, aren't all that different in terms of circuitry and neural processes from those of rats. 

Last Rat Standing (Darwin and Bond in the Age of Coronavirus)

New York City rat (photo by Christopher Sadowski) 
and Javier Badem as Raoul Silva in Skyfall (2012)

There's a lovely scene in the Bond film Skyfall in which the villain, Raoul Silva, played by brilliant Spanish actor Javier Badem, tells the story of his grandmother's solution to the problem of rats when they infest the tiny island on which she lives:

"They'd come on a fishing boat and gorged themselves on coconut. So how do you get rats off an island, hmm? My grandmother showed me. We buried an oil drum and hinged the lid. Then we wired coconut to the lid as bait. The rats would come for the coconut and they would fall into the drum. And after a month, you've trapped all the rats. But what did you do then? Throw the drum into the ocean? Burn it? No. You just leave it. And they begin to get hungry. Then one by one, they start eating each other, until there are only two left. The two survivors. And then what - do you kill them? No. You take them and release them into the trees. Only now, they don't eat coconut anymore. Now they only eat rat. You have changed their nature."

I thought of this when I read about the plight of rats in NYC (and elsewhere) during the coronavirus pandemic. Thanks to the so-called lockdown, many of their favourite feeding places - such as the bins at the back of restaurants - are no longer viable options, forcing these resilient rodents to resort to desperate measures. Not only are they fighting one another for food, but some have turned cannibalistic and are devouring their own kind.

The fact is, the threat of starvation makes rats - like people - behave in extremely different ways; they effectively change their nature, as Sr. Silva would say.

I suppose, in the end, this will give them an evolutionary kick up the arse and result in a future breed of stronger, more aggressive, more resourceful rats (survival of the fittest being the popular name for the mechanism of natural selection we can witness at work here).    

Notes

Skyfall (2012), dir. Sam Mendes, starring Daniel Craig (as James Bond) and Javier Bardem (as Raoul Silva): click here to watch the scene I mention above.

They're in the Trees! (In Praise of Risky Play)

Two Blonde Beasts in a Tree 

 (SA/2019)

It's conker season - a time of the year that brings back fond memories of childhood, throwing bricks and sticks at the horse chestnut trees lining Chatteris Avenue and, if feeling particularly brave, attempting to clamber up them in order to better access their treasures.    

Today, children don't bother collecting conkers; nor do they seem to climb trees, or even go outdoors very much. We live in an increasingly risk-averse culture of health and safety in which unsupervised activity - or what used to simply be called play - is socially unacceptable.

And that, surely, can't be good ...?

In fact, the eradication of genuine play - understood as an inherently joyous but sometimes risky form of freedom - has had a profoundly crippling and depressing effect on children.

Modern parents, teachers, and other childminders may not like it, but children like to climb trees, swing on ropes, ride bikes, handle knives, jump in water, play with fire, throw stones, wrestle, explore abandoned buildings, and generally get up to mischief. And they like to do so without wearing crash helmets and other protective forms of clothing - for even cuts and bruises and grazed knees are an important part of having fun and growing up.          

In other words, forms of risky play have developmental and evolutionary value and can therefore be observed in other young mammals, not just human youngsters. Sometimes, rarely, it can result in serious injury and - very rarely - even have tragic consequences. But the benefits of allowing children to play outdoors and unsupervised far outweigh the dangers; as experiments with rats have clearly demonstrated.     

Children - like rodents - that are deprived of play during a critical phase of their development tend to grow up overly fearful and less adaptive when placed in an unfamiliar environment. Their ability to interact socially with strangers is also not what it might be; they can, for example, be sullen and withdrawn, or quick to anger (i.e., they have trouble regulating their emotions).

Again, that's not good - and surely it's not what anyone wants. Perhaps if children still played conkers and climbed trees, there wouldn't be so many teens stabbing one another, dealing drugs, committing suicide, etc. Such neurotic and psychopathological behaviour surely isn't unconnected to the dramatic decline in childhood play (and the equally dramatic rise of social media).   

The irony of the situation today isn't lost on one researcher in this area:

"We deprive children of free, risky play, ostensibly to protect them from danger, but in the process we set them up for mental breakdowns. Children are designed by nature to teach themselves emotional resilience by playing in risky, emotion-inducing ways. In the long run, we endanger them far more by preventing such play than by allowing it. And, we deprive them of fun."*

* See: Peter Gray, 'Risky Play: Why Children Love It and Need It', Psychology Today (April 07 2014): click here.

On Biodiversity in the Anthropocene

The London Underground Mosquito (Culex molestus)

When you read reports about global warming, the destruction of the natural world and accelerated rates of extinction, it's easy to think that there are no winners other than ever-proliferating humanity and that even our malignant success as a species is unsustainable and will thus be relatively shortlived.

But, actually, there are other animals who are doing OK and might even be said to be thriving in this age that some term the Anthropocene ...

Mosquitos, for example, are well-adapted to life in cities; illegally dumped waste and poor sanitation means lots of stagnant water in which to breed; whilst millions of people and their pets all conveniently packed into one place means a constant supply of warm blood on which to feed.  

Other insects doing just fine thanks to human expansion and activity, include bedbugs and cockroaches. But it's not just creepy-crawlies that will enter the evolutionary future alongside man. Larger animals also find shelter, warmth and plentiful food in urban environments. It has been pointed out that if a rat was to design its own ideal home, it would pretty much resemble the system of sewers we've built for them.

And in the UK, thanks to current forestry practices and the eradication of natural predators, the number of deer is at its highest for a thousand years, with some one-and-a-half million frolicking in the woodlands and suburban gardens (just ask my sister about her plants).

Even when we poison the lakes and pollute the rivers, the cyanobacteria (or blue-green algae as they are commonly known) come up smiling; eagerly exploiting the increased nitrogen levels that result when fertilisers applied to farmland are washed into the waters. 

Finally, it's worth giving a big shout to the cephalopods; for species of squid, cuttlefish, and octopus are also making the most of present conditions. Whilst not entirely sure why their numbers are rising, scientists think it's likely due to the fact that the oceans are warming - thanks to human activity - and because we're significantly depleting the numbers of those animals that usually prey on the above.

In addition, celaphopods are natural suvivors; highly intelligent and extremely adaptable creatures who have been around for approximately 480 million years (cf. the pitiful 200,000 years chalked up by modern humans).  

In brief: although some like to imagine an apocalyptic future in which the earth is devoid of all life apart from human beings and their parasites, there is evidence to suggest that things won't be so grim; that large scale and drastic changes to the environment can, in fact, give evolution a real kick up the arse, resulting in new and more resilient species (often as the result of hybridization).

Of course, there probably aren't going to be any charismatic megafauna outside of zoos and conservation areas, but the process of natural selection will almost certainly ensure the survival of life at some level and in some form. Indeed, to return to our friend the mosquito, a sub-species has been discovered living in the London Underground of all places; while you mind the gap and worry about saving the whale, she pierces your skin and drinks ...    


Notes 

Those interested in this topic might like to see the recently published book by Professor Chris D. Thomas; Inheritors of the Earth: How Nature is Thriving in an Age of Extinction, (Allen Lane, 2017). 

For a fascinating interview with Prof. Thomas on the Vox news site (Dec 15, 2017) click here.