Strandbeesten are like really big toys that you can play with on the beach! They are like big creatures made out of sticks and tubes that can move all on their own, kind of like robots.
You know how you can move your arms and legs to walk and run? Strandbeesten do something similar, but the way they move is called "mechanical." This means they have some special parts inside that make them move without someone controlling them.
A man named Theo Jansen made the first strandbeesten. He was really interested in how creatures in nature can move and not fall over, and he wanted to make something that could move like that too. He used things like PVC pipes and bike wheels to make the strandbeesten's legs and body, and it's a really creative way to make something fun with everyday items!
Now, people all over the world enjoy making their own strandbeesten and playing with them at the beach. Some people even decorate them with fun designs. But it's also important to be safe and respectful of the natural environment, so make sure to always clean up any materials you used and don't disturb any animals around you.