Subtitles section Play video Print subtitles You might not want to think about this, but over 3,500 species of cockroaches live on this planet. The good news? Only about 30 of those species have adapted to live around humans. The bad news? Thirty species of cockroaches can live around us! Roaches are one of the most common pests in the US. So it's no surprise that humans are always trying to kill them. But no matter how many times we stomp them, squash them, and bomb them with toxic chemicals, these pesky pests always seem to pop up time and time again. So what's going on? Let's take a closer look at the roach you probably know better than you'd like. Periplaneta Americana, aka, the American Cockroach. But this name is misleading, this guy is actually from Africa, not America. It made its way to the US by infesting boats in the 16th century, and it's been spreading to almost every corner in the world ever since. Turns out, it's one of the largest species of cockroach around. But that's not the only big thing about it. New research has revealed that it has a massive genome, one of the largest of any studied insect. And many of these genes are exactly what make this roach a master survivor. Let's start with the genes associated with something called Chemoreception. That's how roaches smell and taste their environment. Turns out they're actually way better sniffing out and eating food than most other insects. The American roach has 154 olfactory receptors for smell, and 544 gustatory receptors for taste, more than any other insect on the planet. As a result, these cockroaches are not picky eaters. Sure, they like cheese, meat and sugar like the rest of us, but they'll also go for things like cardboard, book bindings, human toenails, rotting meat, blood, excrement, and even each other. That's right, these roaches have been known to eat other dead or crippled cockroaches, all in the name of survival. It sounds gross, but this diverse diet makes it easy to find a meal just about anywhere, even if it's poisonous to most animals. This roach has a bunch of genes called Cytochrome P450s, which help it withstand poisonous chemicals, like peppermint. These genes code for detoxification enzymes, which keep the insect safe. On top of that, this roach has a super-strong immune system that seeks out and kills harmful microbes and fungi, making the most unsanitary environment look like a five-star hotel to the American cockroach. Not gross enough yet? Well... consider this. Cockroaches can live nearly a week without their heads. Yeah, that's not a myth. They don't have a highly pressurized network of blood vessels like humans, so they don't bleed out. Instead, their necks actually seal off the opening. They can't regenerate a whole head, but roaches do have an impressive set of regenerative superpowers. For up to the first two years of its life, the American roach goes through a series of regenerative molts as it matures into an adult. During a single molt stage, it can replace lost limbs. And over a series of molts, it can regrow antennae and even its eyes. Roaches may be hard to kill, but there's an easy way to keep them clear of your kitchen. Cleanliness. A roach won't just survive in unsanitary conditions, it actually enjoys it. Its heightened senses mean it actually relishes rotting food. So, store food in airtight containers. Cover trash bins, and keep your basement dry. It might also be smart to plug holes in your walls, unused electrical outlets, and especially drains, since get this, roaches can use your plumbing to climb up from sewers into your bathroom sink. It might not eliminate the risk entirely, but it can't hurt, and it will certainly make you feel better. However, we can't promise it will keep them out of your nightmares.