I've heard of some insurance companies that test for nicotine use. Even though they may ask about tobacco use, and you can say no....of course the nicotine will show if a test is done.
Once, I was asked to do a urine test at a company I already worked for...I asked why..."You suspect me of something?" Boss man said no, but the new Insurance company we switched to requires it.
I told him I don't do urine test but, I'll give 'em a taste test if that'll help them out. He just looked at me with this quizzical, disturbed look and walked off. I was never approached again about it at that job. About two months later, I left that job and started my own company. Of course, that was diff type of Insurance. Still, it was funny...lol