Great clarification!! I knew it was wee but why it passed solidly sometimes stumped me!!In humans, we happen to excrete nitrogen in the form of urea, which is water soluble. Which is why we tend to think of 'wee' as being liquid!
Reptiles on the other hand excrete nitrogen in the form of Uric Acid (known as urates) - which can be excreted dry.
Both methods fulfil function, just that one compound gets dissolved in water and the other doesn't so much!
What makes table salt white?What makes it white though?