On a crummy summer day a few weeks ago we decided to get some lunch with the kids and then visit the local pet store. The first thing we did was visit the puppies and kittens but we mainly hung out in the back of the store where the fish were.
I carried our 6 month old daughter around to see the fish as well and focused on the brighter tanks with bigger fish. Our two year old son ran around going from tank to tank saying "Fish, Fish!" and then moved on to the next room with... more fish! As it turns out, our son is starting the stage where he is afraid of things so the bigger fish scared him a bit.
This was a great activity to do indoors without spending money. It's not something we'll do often because eventually we'll end up bringing a fish home I'm sure but it was a fun change of pace.