ants were in your setup?? yikes, how were they getting in? what was your lid like?
for the future, if you plan on getting another salamander, flood a patch of grass with your hose to obtain worms...or just wait for a good rain...
Or, if you have a blowtorch, stick about 2 feet of a steel rod in the earth and heat it with a blow torch really really well...(If you are underage, HAVE A PARENT DO THIS!!)
It is my tested and true method of obtaining free fishing bait, and now, food for my sallies. I get about 150 worms everytime. Stick the in a garage fridge in some loose moist soil.
Good luck, and I am sorry about your loss.