A few years ago I was on a bicycle trip when I got off my bike for a rest. I sat down on the grass. A few seconds later, I was covered in ants. They were swarming all over me so I got up and brushed them off. It was a strange experience but I soon forgot about it. A couple of years later, I was living in Jordan. I had just moved into a modern flat and was unpacking plates when I saw something move out of the corner of my eye. I looked over at the kitchen drawer and there was a cockroach crawling out of it. I screamed. Then I grabbed a can of _ and sprayed it on the cockroach. He ran under the nearby bathroom door. It took me three days before I found the courage to open the bathroom door to see if he was still alive. He wasn't. Why did I react so violently to one lone insect when a closer encounter with hundreds of ants hardly affected me? The answer is easy: because cockroaches are creepy  crawlies and ants aren't. Creepy crawlies are those little bugs which cause feelings such as anxiety - they make your skin crawl. Did you know that some people feel such a fear of bugs that it becomes a phobia ? Psychologists have offered many explanations. Some say we associate them with dirt and disease. Or that these are life forms that are so alien to us, that we find them disgusting for their dissimilarity. Insects, however, don't follow our rules - they just do what they want and invade our space. Unfortunately, although insects and bugs have been a successful animal species up to now, many of them, like many other species nowadays, are under threat of dying out. Entomologistswarn that this could upset entire ecosystems and lead to all kinds of disastrous consequences. So my advice to you is: the next time you feel the urge to stamp on, splatter or spray a creepy crawly, give a thought to the planet and stop. .. Why did the author mention the ants in the beginning?
Because the experience with the ants presents a sharp contrast to that with the cockroach later. Because the author wants to show her preference to the ants and her dislike for the cockroaches. Because both ants and cockroaches are creepy crawlies that the author dislikes. Because meeting the ants is an unusual experience that the author can hardly forget.