Q: We have been finding droppings around our house, on the driveway and in our unfinished basement. The droppings are black, approximately one-eighth inch in diameter and less than one-quarter inch long. They are unique in that they have white tips on them. Could it be lizard droppings? We have seen a lot of them around our house.

A: You are correct. Lizard droppings have white tips due to the process of reptile elimination: both feces and urine exit their body through the same opening: the cloaca. Lizards are very water-efficient and their urine is quite concentrated. The white tip on the droppings is uric acid crystals.