Urine typically is yellow, but in combination with blue dyes, a green colour can be obtained.

Noteworthy compounds are methylene blue, thymol, Cimetidine (antacid), or Mitoxanthrone (used in cancer therapy).

I've mentioned these just for the sake of completeness - I think it is irresponsible and stupid to spike food with anything that doesn't belong there.

Hiding a webcam in a shelf and running zoneminder probably isn't legal either and will get you in trouble with the privacy officer, but at least that doesn't mess around with the health of anybody else.

Looking for a compound
I've created a taxonomy called "topics" which has 4 top level terms:


science
environment
technology
cant remember the last one


and each of those terms will have child terms. I want to be able to lock down the top level terms but not the child term. 

Basically editors should be able to create as many terms as they want for each of those top level terms.. But those top level terms cant be deleted or modified.

Is that possible?
