Drats

Drat.
Rats.
Drats.

Something you can shout if you're overrun with rodents (and you feel "rats!" would be too unoriginal).*

Vermine.
Infestation.
Verminfestation.


* No need to be too concerned with originality** when dealing with rats, as they are the original plague-arisers.

One rat sees another rat spreading disease, then goes and spreads the same disease.
Copycat.***

Bubonic.
Icky.
Bubonicky.


** Appropriately, the idea for this post came from the brain of a friend, not my own.

Ironic.
Nice.
Ironice.


*** A copycat is actually the best way to get rid of plagiarizing rats.

Mews.
Useful.
Mewseful.