We have never had dog or cat - my dad loved dogs and was always threatening to bring us one.
Did have two cold water tanks with fish in - containing a Tench, Carp, Crayfish, Stoneloach - linked to my husbands job at the time and as interest for our children.
My daughter had 2 Hamsters and a few Russian Hamsters - you can keep the russian ones together they were quite cute.
She was pretty good on cleaning them out - i usually did the fish tanks.
Ghiro x