They're doing what they're supposed to be doing. Kids test limits - it's part of brain development. It's a good thing.
Try not to take it personally- instead fill up your toolbox with strategies that can work in the moment to redirect them.
Remember - behaviour is always communication. Do they want your attention? Are they bored? Are they wondering what this sounds like when it's banged? Are they asking "what will you do if I do this, mummy?".
You can pass this test by seeing it as just that - a little test. A message. That you can redirect and support without burning bridges.
If redirecting by telling them what they can do doesn't work - then ok - it's time for you to gently step in and stop them. Not with threatening or with malice - with the vibe of "ok you're struggling with your impulses and I'm here to help you and get to the bottom of what you need".
Try it! Tag a parent who's struggling with big behaviours.
Watch the full reel here