(Picture taken from http://listverse.com)
The popular cartoon series, Tom and Jerry, depicts hilarious fights between two arch enemies, a cat and a mouse. Sharing predator and prey relationship, this bubbly pair is always seen plotting against each other with uses of explosives and nonsensical traps. One can say that these two, are much too close for comfort. However, in reality, this pair – mouse (Mus musculus) and cat (Felis catus) – may actually be as close.
Research has found that by making genetic changes in mice’s sense of smell, we can remove its fear of its predator, the cat. As a result, mice can scatter around a cat freely, without any sense of fear. This research highlights that mice’s fear towards cats is both instinctive and learnt. Hence, if genetic changes in mice’s smell of smell could remove its aversion towards cats, it implies that alteration to mice’s instinctive behaviour overrides any other learnt behaviour to escape from its predator.
Alternatively, other sources indicate that parasites could cause a similar behaviour alteration in mice. Toxoplasma gondii, a parasite that is found to attach to mice, can alter its hosts’ behaviour by making them more active and even a preference for cat odors! Rodents act as intermediate host reservoir for the parasite while its definitive host is actually the Felis. In order for the sexual reproduction and maturation of the parasites to be completed, the parasite must be eaten by a predatory definitive host. Thus, in manipulating its intermediate host’s, the mice, behaviour, the transmission from intermediate host to definitive host is enhanced, thus increasing the parasite’s chances of reaching maturation and engaging in sexual reproduction.
While rodents may seem to have a fatal attraction towards their predator, it is unsure if this love will be returned on the side of the felines. Nevertheless, let’s hope that they will have a blissful marriage, till death do they part.
1. “10 Fascinating Cases of Mind Control,” by Nauplius. List Universe, 29 Jul 2009. URL: http://listverse.com/2009/07/29/10-fascinating-cases-of-mind-control/#commentbox (accessed on 25 Mar 2010)
2. “Cat and Mouse Make Friends,” by diagonaluk. YouTube Channel, 28 Jul 2008. URL: http://www.youtube.com/watch?v=Nq1TusgAIqM (accessed on 26 Mar 2010)
3. “University team creates mutant mouse with no fear of cats,” by S. Connor. The Independent, 8 Nov 2007. URL: http://www.independent.co.uk/news/science/university-team-creates-mutant-mouse-with-no-fear-of-cats-399447.html (accessed on 26 Mar 2010)
4. J. P. Webster, 2007. The Effect of Toxoplasma gondii on Animal Behavior: Playing Cat and Mouse. Schizophrenia Bulletin, 33(3):752-756