Some cat behaviorists advise against toilet training because it restricts the owner from monitoring changes in the cat's urine and feces (which are often related to the health of the pet). Another criticism is that toilet training can cause various stresses to the cat, partly because using the toilet goes against a cat's natural instinct to dig and cover its own feces, and because the toilet seat can be physically difficult for cats to straddle (especially those who are old or ill).[3]