Why would a dog like to eat worms in the garden dead or alive?

It is ideal, especially if you see your dog drinking and urinating excessively (difficult, I know, due to your living situation), that you take her to your vet to have some bloodwork and urinalysis done as that will relieve your anxiety regarding kidney failure. If you can bring in to the vet the first urine sample of the day, that tends to be more concentrated and can be a good indicator of kidney function. I would not worry too much about the worm eating - just extra protein! :-) It is hard to imagine what they would find attractive in eating worms, but that's a dog for you! It sounds like the aggression was possibly caused by a food allergy/sensitivity, so it is wise to switch the food back. Good luck to you - hope the blood tests are normal!