I definitely know when Diamond has to go because she will circle about 100 times (literally) before she finds her spot. Then she wiggles the two back legs until she finds the perfect spot. I always know when she is done because she feels the need to dig whether it's pee or poop. This is how I know she has an accident too in the house because I hear her digging!
She is not completely house trained yet but she is getting there!