Do you find yourself drawn to things spooky and dangerous? Do you, like me, sometimes-especially on Monday mornings-feel like a zombie, with no will of your own? Rats go through this all the time. When a rat becomes infected with the parasite called toxoplasma, they start to like cats-especially the smell of cats. Of course, if they are drawn to the smell of cats, they are likely to be eaten by a cat.

Being eaten by a cat is exactly what the toxoplasma parasite wants. It lives in the part of a rat’s brain that controls emotions, but it cannot reproduce in the rat. It has to reproduce inside a cat’s intestines. Incredible as it seems, the parasite changes the rat’s natural fear of cats into a fondness for the smell of cats and insures that it-the parasite-will find the place it needs to raise a family of little parasites.

I am now concerned about my own fondness for cats-and also dogs. Is it me who likes them, or is it some tiny parasite? Is that why I cannot resist feeding cats and dogs, taking them to the veterinarian, and-zombie-like-cleaning up the stuff they leave in the yard? Does my fascination with saber-toothed tigers have anything to do with this?

On the lighter side, I learned, while researching this topic, that it is possible to purchase cat urine in bulk. It is cat urine that attracts an infected rat and, if you are going to do a thorough study of this subject, I suppose it would be necessary to purchase cat urine in bulk. Now that I think about it, I believe I have seen railroad tanker cars labeled, “Danger: Bulk Cat Urine”.

In the natural world, there are other examples of parasites changing the behavior of their hosts to benefit the parasite, but previously discovered examples of it have always been in insects and things like snails. Grasshoppers, for example, are afflicted with a parasite that makes them jump into water where the adult parasite-a hairworm-reproduces.

Another kind of parasite turns an ant into a tasty looking berry. Birds, thinking it is a tasty berry, eat it and then transport the parasites to a new location. Let us not forget zombie cockroaches. A wasp sting to the cockroach brain turns them into living hosts for the wasp’s offspring.

Is it just me, or do people with colds always want to get closer to a healthy person and shake their hand? What makes them think that I, too, want to be infected with another cold virus or bacteria?

Lest you think all these parasites are bad for us, a strain of bacteria found in yogurt-lactobacillus-seems to make naturally moody mice less anxious and depressed. You are probably as surprise as I was to find that, along with bulk cat urine, you can purchase naturally moody mice. I believe these are the ones that, in addition to being depressed all the time, tend to overeat and get fat. If you should be so unlucky as to own a glum, irascible mouse needing to go on a diet, a daily dose of yogurt may well turn him or her into a cheerful, laid-back mouse.

To no one’s great surprise, my wife has now prescribed a daily dose of yogurt for me and, in addition to being less irritable to those around me, I have taken to taste testing all sorts of different yogurts. Curiously, I have also developed a sudden interest in Hawaiian music, hula dancers and sauerkraut.

Scientific research will, some day, unravel this mystery, too.

Rhinelander District Library Director Ed Hughes is available at (715) 365-1070.