Cockroaches are the only animals on earth that can survive in all kinds of adverse environments. A long time ago I read in a newspaper that when a stone is placed in the stomach of a cockroach, the stone is also digested. I was surprised to read the news that day. It is very nice to see that you have prepared a very nice medicine to repel cockroaches and presented it to us. And a nice discussion about the effects of insects. Best wishes for you.