They can get into anything - months after we had them we found dead ones inside the salt pot urgh! Crawled through the little hole in the top - tiny hole for salt to come out. We found them under the rims of jam jars as well. The house we were in at the time had foam cavity insulation and they were nesting in the foam and coming out into the house through tiny little cracks between the wall and window. About 8pm every night it was like a scene from that Tom and Jerry cartoon, if you've seen it - there would be a trail come down the wall, across the carpet, round the table, into the kitchen and up the kitchen table leg - a moving army! 3 days after we put the nippon down - not one. They eat it and feed it to the eggs and queens who then die.
The second incidence was later in the summer - July/August and the eggs had already hatched so we got flying ants. Are yours flying ones or crawling ones? If they are crawling ones, work out where they are coming from and put that Nippon stuff down. If they are flying ones I think you'll just have to move the tanks to a different room. Fly spray works on them but obviously that is bad for hamsters. I used to hoover them up!
I suppose if there are only the odd one or two she might eat them
Are there a lot?