Rat
A rat stands for wealth and diligence, and at the same time for what quietly leaks away. A rat carrying grain, or a white rat, is a good omen of money gathering; something gnawed by rats warns you to check where your money — or your trust — is draining.
Rats in the granary once meant there was grain to begin with, so the dream was never read as purely bad — but gnawing was read as a clear warning. The rat's color and what it is doing decide the branch.
Readings by Situation
Seeing a white rat
The most auspicious of rat dreams. Read as unexpected money or the help of a benefactor, and as a season when long preparation bears fruit. A white rat entering the house is better still.
A rat carrying grain or goods
Read as money gathering. But a rat carrying things out of the house means the opposite — money leaking — so the direction of travel is what matters.
A rat gnawing at something
A signal to look at leaking expenses or someone slowly eating into what is yours. A good time to review subscriptions and dues that escape notice; tradition put it as minding the granary.
Being bitten by a rat, or catching one
A bite means a small loss or gossip, but is not read as badly ominous. Catching the rat means stopping the leak, and is read as fortunate.
Rat dreams read as a picture of money coming and going. If you are actually worried about your finances, your spending record deserves a look before the dream does.