Insects
I am sure I am not the only mother with a son interested in insects. There is so much that you can learn from them and I can see how they can be fun and yes, a little gruesome.
Our favourite topics include naming the body parts (wings, legs, antennae, mandibles) which leads to discussion on modes of transport (jumping, flying, walking) and then onto diets, prey and who eats who!
These insects are played with almost daily and are stored in a container on our outdoor shelves. We do have matching cards that correspond to each insect, but mostly I find them like this... all lined up in a row.
We originally bought these in a pack but I notice that similar insects can be found at Mini Zoo.