Cases of animals being infected by behaviour-modifying parasites are popping up throughout the animal kingdom, including zombie ants and rats that become sexually attracted to cats.In an even creepier development, a virus affecting caterpillars is beginning to change behaviours as well, making it the first classic example of a zombie infection come to life.
According to Ars Technica, virally infected European gypsy moth caterpillars behave in a way that their healthy brethren never would. The virus makes the caterpillar climb to the top of a tree, die, and liquefy, so the virus can spread to other caterpillars via rainfall. Normally, these caterpillars stay deep in the soil or tree trunks to avoid detection — but in order for the virus to propagate it needs to find a way into new hosts.
Scientists identified the “egt” gene as the affected area of the caterpillar brain. Removal or insertion of the gene caused the caterpillar to either continue regular function or to climb to the highest point in the area to die, respectively.
On the other hand, the aforementioned zombie ants are infected by a fungus that drives the ant to stumble drunkenly through the forests of Thailand. The zombie ants take a bite of a leaf around noon — cued by either sunlight or humidity — and remain there with their mandibles clenched until they die at sunset, allowing the fungus to spread to the leaf.
A particularly twisted single-called parasite called Toxoplasma gondii infects rats. The parasite, which can only reproduce in cats, causes their hosts to pursue, rather than run from, their natural cat enemy. The cat eats the infected rat, allowing the infection to live on.
When the rats smell cat urine, they normally freeze and then run. But the infection activates the sexual arousal part of the brain instead, giving them “fatal feline attraction.”
Doctors say that humans are not affected by Toxoplasma gondii in the same way as rats, though there are reports linking Toxoplasma to schizophrenia.
NOW WATCH: Briefing videos
Business Insider Emails & Alerts
Site highlights each day to your inbox.