Each electron in an atom is described by four different quantum numbers. The first three (n, l, ml) specify the particular orbital of interest, and the fourth (ms) specifies how many electrons can occupy that orbital.able of Allowed Quantum Numbers. n l ml Number of orbitals Orbital Name Number of electrons 1 0 0 1 1s 2 2 0 0 1 2s 2 1 -1, 0, +1 3 2p 6 3 0 0 1 3s 2 1 -1, 0, +1 3 3p 6 2 -2, -1, 0, +1, +2 5 3d 10 4 0 0 1 4s 2 1 -1, 0, +1 3 4p 6 2 -2, -1, 0, +1, +2 5 4d 10 3 -3, -2, -1, 0, +1, +2, +3 7 4f 14.
Rat droppings are a key sign of a rat infestation; the mess and debris they leave in their wake is unmistakable. In addition to scattered nesting materials; debris from chewing, feeding and gnawing; rodents excrete urine and feces every few steps they take along their habitual paths of travel.
I recommend that you have the droppings cleaned if they are in high numbers, due to the odor and biohazard that they cause. Not only can new rats smell the odor of previous rats, but the droppings may be dangerous to people. Rats also urinate, of course, and one rat can urinate up to three gallons per year. Rats often travel the same routes over and over again.