... Q: What is the similarity between men and rats? A: Both keep searching for new holes. Q: What is the closest thing similar to a woman's period? A: Your salary, it comes once a month lasts about 5- days and if it doesn't come, it means you are in big trouble. Q: What's the difference between biology and sociology? A: When the baby looks like his dad or mom, then it is biology. When the baby looks like the neighbor, then it is sociology.