Whilst I also find that ants can be a bit of a pain in the garden, and elsewhere some good can come from them - Fish Food. As a youngster I remember buying dried ants eggs for my goldfish. I wouldn't dream of dropping ants or eggs in my aqauriums but the pond is a different matter and my fish enjoy a tasty treat.

My house is festoned with ants, some probably get into the aquariums too. I don't think my fish are interested.