Cockroaches as Pets

from Gordon Ramel

It is true cockroaches do make great pets, they don't bite, carry disease, need taking for a walk, dig up other people's gardens, defecate in the street, or attack children. On top of that, they take up very little space and cost less to feed and maintain than a cat, a dog or even a budgie, and there are no vets bills. There you are, what are you waiting for, rush out and buy one now while they are still cheap, you can finish reading this piece later.

Apart from people who are seriously into 'roaches, perhaps the commonest roach in captivity is Gromphadorhina portentosa, the Madagascan Hissing Cockroach (Hissers). This is a large wingless, and relatively slow moving species from Madagascar. It may seem strange to those not familiar with it, but Hissers (besides being amazing) are definitely cute and are often considered beautiful and highly lovable. There is something about a 7 or 8 cm long and 2 cm wide cockroach sitting quietly in the palm of your hand almost purring as you stroke it that gets to some people in the most amazing way. Sometimes it is hard to get a cockroach back from someone when they fall in love with it, despite the fact that it took you almost half an hour of cajoling to get them to hold it in the first place. There are generally nymphs eager to leave home, though, who can be packed off with any new 'love at first sight' roachophile. Though these may be a bit faster on the leg, they soon get to enjoy the warmth of a human hand and can easily be convinced to eat daintily from a piece of stone fruit or banana while you hold them. Though a lot of cockroaches are amazing and fun to keep, Hissers are just fantastic. If you have never seen one in the flesh or held one in your hand, you are missing out.

Apart from Hissers, there are several species of Blaberus (Blaberus craniifera = the Death's Head Cockroach, and B. discoidalis = the Drummer) which are easy to get hold of and to keep as well as being large enough to amaze your friends. These do have wings, and that puts a lot of people off, because even though they fly only very weakly, they look more like your archetypal yucky cockroach. They are more active Hissers and therefore a lot harder to hold, however if you don't actually have to cuddle your pets, (and who cuddles the canary?), Blaberus sp are wonderful animals to keep.

The trouble with cockroaches is not really with cockroaches at all, but with people. Of the 4,000 named species of cockroach, only about 25, or less than 1%, are recognised pests. The unfortunate fact is that these are the only cockroaches that most people meet, and that by their very nature (most pest species originated as cave dwelling species) they are very good at living in human habitation ... thus it is that human/cockroach relations have been pretty bad since the first one began a long time ago. I would not want some non-human intelligence to judge you, me or our society on the basis of a sample consisting entirely of politicians or professional criminals. This really is the take home message of what I have to say about cockroaches and there is a lot yet to be discovered, so don't judge the book by its cover, most cockroaches are valuable members of the planetary ecosystem, and they deserve a better press.

Despite belief to the contrary, cockroaches are not inherently dirty, what they are is extremely scared of you and me. This is partly because to many animals, particularly monkeys, a cockroach is a tasty mouthful. Because of this, cockroaches have evolved to be fleet of foot and to live in inaccessible nooks and crannies. These sorts of places inevitably collect dirt and garbage, and stay damp longer once wet, but the cockroaches do not choose to live there because of the dirt, they just put up with it. The dirt is lived in and fed on by a variety of micro-organisms and some of these inevitably get transported around on the cockroach's feet and legs. When the cockroach is out at night looking for something to eat in your larder, some of the micro-organisms get left behind in your food where they flourish. This is not the cockroach's fault any more than it is yours. There are no diseases known to be transmitted by cockroaches in the way that malaria is transmitted by mosquitos.

Most people seem to expect cockroaches to be slimy to the feel and are amazed to discover they are nothing of the sort. In fact, Hissers not only look like a piece of polished wood, but feel like one too. This is because like anything else that lives in places that are damp and warm, cockroaches are subject to attack from micro-organisms and one of the ways they protect themselves from this sort of attack is to have a thin layer of wax over their cuticle, that is secreted by special cells beneath it. Wax is known to have antibiotic properties, and as well as this it helps to keep out unwanted water and it forms a physical barrier to the micro-organisms as well. Having said that, I will admit that the smell originating from large numbers of pest species such as Periplanata americana and its relatives is rather unpleasant. However, Hissers and Blaberus sp, if kept clean, will give off little if any smell at all.

Another commonly kept species is the Surinam Burrowing Cockroach (Pycnoselus surinamensis) which is a smaller, faster moving species and which also has wings, but I have never seen it fly. It is easily kept in a sweet jar two thirds full of soil and fed on fresh fruit and vegetables. You will have to put some red cellophane around the jar if you want to watch all the time, otherwise keep them in the dark and just take them out for an occasional watch. They do and will burrow to the bottom of the jar, they are also parthenogenic, meaning that there are only females who lay unfertilised eggs which develop into other females and so on. Personally, I consider this to be an ecological stop-gap measure which evolved because it allowed isolated colonies of a particular species to survive as only females until more males could be recruited into the population from outside, rather than a major evolutionary step forward leading the way to a society without males. From an evolutionary point of view, it has the effect of limiting the genetic variability and flexibility of the species, thus reducing its chances of dealing successfully with changes in the environment. Having said that, there are currently a species of Gall Wasp and Saw-Fly in Britain and Europe and Stone-Flies in Lake Baikal among others for which males have never been found, though what effect this is having on the success of the species concerned is not known. Considering that species tend to last about ten million years at best we know evolution and the machinations of life are often too majestic for the human mind to span or correctly interpret.

Having been given this chance to write something about cockroaches, I have to take this opportunity to dispel a couple more myths. A few years ago, I had a job in a touristy sort of place where I spent all day getting people to hold Hissers and a variety of even bigger Stick-Insects. One of the commonest statements people would make when they discovered that I had cockroaches there was (apart from telling me about the 50 cm long ones they saw on their last holidays) was, quote, "roaches, they're the only thing that would survive a direct nuclear hit, aren't they?" The answer is, of course, no, the temperature at the centre of a nuclear explosion is around 12,000,000 degrees C and not even cockroaches would survive this. I believe this originates from a television documentary which mentioned that cockroaches have the highest ability to survive radiation poisoning of those animals so far tested. But to say that roaches would be the only living things to survive a nuclear war is ridiculous, many micro-organisms would survive far longer than cockroaches, as would many other far simpler organisms, because, apart from anything else, what would they eat?

The second myth I ran into a lot is, quote,"you gotta watch it when you stamp on one of them things or else the body breaks up and the bits turn into tiny roaches and run away and you end up with more than you ever 'ad before". Quite how this piece of urban mythology came into existence, I am not sure, but I suspect that somewhere, maybe more than once, someone stepped on a gravid female which released its soon to be hatched young while it was dying. Cockroaches lay their eggs in a sort of polystyrene egg box, in some species the female then retains this 'ootheca' within her body until the young are ready to hatch. Considering the number of cockroaches that get stood on every year, it is quite reasonable that some of them should be carrying young sufficiently close to hatching for them to be able to escape from their mother's dying body. Even under normal circumstances, the emergence is very quick.

Like all insects, cockroaches moult or shed their skins occasionally as they get older. Sometimes if you are lucky and it cannot find a large enough space under a log or if there are a lot of cockroaches in the tank, you will catch one shedding its skin during the day and where you can see it. This is an amazing process to watch and takes about 30 to 40 minutes to complete, the newly emerged cockroach is milk chocolate white, quite a contrast from its old skin.

Cockroaches are easy to keep as well as providing a lot of fun and a good way to enhance the children's natural fascination with the animal world. All you need is a small fish tank with a closely fitting fine-mesh topped lid and a heat mat. Inside you want 2 cm of vaseline around the top, 3 cm of wood shavings in the bottom, a couple of pieces of bark for them to hide under, somewhere for them to get water from (a small shallow dish sank into the wood shavings so that it is flush with the surface and filled with cotton waste as well as water is fine), and a regular supply of both dry dog food and fresh fruit and vegetables.

For more information on looking after your cockroach pets, see Caring for Cockroaches and for general information on the whole group see the suborder Blattodea.

P.S. You can reach me by e-mail at: G.J.L.Ramel@exeter.ac.uk