The extent to which animals are used for science in Aotearoa is incredibly broad and with only 36%* of Kiwis knowing that animal experimentation even happens here, we have a long way to go in terms of awareness and educating the public.*According to data obtained via a public poll that we commissioned in 2019.
To help educate you and as many other people as possible, on top of our campaigns and other planned mahi (work), we’ll be focusing on a particular topic/issue bimonthly with the sole purpose of teaching you all something new.
Today our Arotahi (focus) is on rats and mice. Read on to learn something new about these special animals!
THE EXTENT TO WHICH RATS AND MICE ARE USED IN NZ
In 2020 (the most recent data we have), 48,993 mice and 7,107 rats were used for science in NZ. A staggering 95% of these mice and 84% of these rats lost their lives. An additional 105,533 mice and 21,602 rats were bred for science, never used, and subsequently killed during 2020.1
With such high numbers of these animals being used and such a high death rate, I can imagine you’d be asking yourself why – why are so many of these animals used and killed?!
WHY RATS AND MICE ARE USED IN SCIENCE
Mice and rats are commonly used due to their small size, low maintenance (i.e., they are easy to house and care for), short life cycle, and ability to breed quickly (allowing large numbers to be generated for studies quickly). They also share many of our genes.2 But that's not surprising, even cats share many of our genes.3
Sadly, the vast knowledge about their genetics and their short breeding cycle makes them good targets for genetic manipulation. This is not only a profitable market, it is also fuelling animal-based research by creating new ways to try and model human conditions.4
However, we know that the use of animals to try and model people fails over 95% of the time!5
A few examples proving that mice and rats aren’t good models for humans:
- Mice are used to develop treatments for inflammatory diseases, such as sepsis, burns, and trauma, but over 150 clinical trials, and billions of dollars spent, have resulted in no effective treatments for humans. This failure is believed to be due to the differences in how mice and humans respond to inflammatory conditions.6
- Because viruses do not affect all species in the same way, human infections cannot be effectively studied in other species. For example, mice do not contract Ebola easily. So researchers adapted the virus to target mice, and they also created transgenic mouse lines with human genes that are more responsive to Ebola. Yet, this failed to produce any useful findings.7
- Tiny transport mechanisms inside the cells work slightly different in humans and rodents.8 This caused 5 deaths in a Hepatitis B drug trial because animal models did not pick up on the toxic effect.9
- Despite their popularity as a model for Type 2 diabetes, rodents’ glucose metabolism works quite different to ours. From the genes encoding insulin production, metabolic pathways, and functions of the pancreas to the speed of disease progression.10
We can easily look at mice and rats and compare them to humans – although we are all capable of pain, fear, and a wide range of emotions, we are NOT the same and can not be swapped out for one another as placeholders. We simply are not 70kg rats or mice.
For example, did you know that mice can’t vomit?11 Mice can even create their own vitamin C within their own bodies without extracting it from their diet – something we are incapable of.12
Mice and rats are beautiful animals with skills and traits that may surprise you…
FUN FACTS ABOUT MICE
Mice are chatty
Mice are intelligent animals with complex levels of communication, many of which remain unclear. Male mice often “shout” across greater distances, while female mice seem to prefer to talk face to face.13
Mice are athletic
Mice are very nimble animals and can run very fast. They can reach a speed of 12 kilometres (7.5 miles) per hour.14
Mice sing love songs
Male mice “emit” ultrasonic vocalisations towards a potential partner that are similar to birdsongs. These songs have several syllable types organized into phrases and motifs.15
FUN FACTS ABOUT RATS
Rats are ticklish
Rats chirp in ultrasonic frequencies when tickled, but they need to be in the right mood to enjoy being tickled. Stressed rats won’t chirp when they are tickled, while rats in a good mood will even chase after the tickling hand to get more!16
Rats are smart
Rats can assess their own knowledge; this is called metacognition. They can reflect on their choices and regret decisions.17
Rats can even enjoy playing hide-and-seek with humans!18
They can outperform us sometimes too. In an experiment, humans and rats had to sort patterns into categories and while they took a bit longer to learn the rules, the rats did better at this task than the humans.19
Rats have empathy
Rats are incredibly social, and studies have found they really care about each other. Rats are capable of helping other rats, even if it means helping a friend over a chocolate treat!20
The key takeaway message here is that although rats and mice are sentient like us, they aren’t mini versions of us humans! We can’t be swapped out for one another in research – just imagine studying a group of humans to try and understands rats or mice better… it simply doesn’t work!
Rats and mice are wonderful animals who are often misunderstood. Sadly, they are commonly exploited in science but together, we are working hard to change this.
