Incorporating some of what u/aksss stated, don't let them freely and peacefully hang out there or it will be a habit and be harder to stop. They will understand

Incorporating some of what u/aksss stated, don't let them freely and peacefully hang out there or it will be a habit and be harder to stop. They will understand at some point. Always be calm and gentle, while also very firm and clear, when you correct their undesired activity. If you get mad, they will instinctively get scared for their life that the 15x heavier giant will lose control of themself in anger, and kill them. You know you won't hurt them, but they don't know that - in the animal world, animals get killed suddenly by larger animals out of sharp anger. Plus, when you need to discipline them in the future, they won't run away and make it way harder to correct their behavior. Some behaviors, the only way is prevention. I still can't stop the cats from sometimes running into unwanted areas of the house, so most of the time I must block them. When they get past, I just let them check out the area for a bit then they eventually let me nicely pick them up and move them to the proper area. Perhaps a more firm owner could employ a better strategy, but this is much better than before. Before, they would escape into the house for 10+ minutes while I got very frustrated at them, they were scared to let me pick them up, and it was just an all around bad experience. Now, they know that when I pick them up, I'm petting them and it can even be a small bonding experience. On another note, the cat's behavior (meowing in your case) may be due to a different underlying need. One big thing I can think of is, is it bored? We humans spend a lot of time entertaining ourselves, cats have the same needs too. I try to have one 30m session of exciting cat wand play a week at the very least. Indoor cats might be better with a little more. Hunting is so, so fulfilling for these animals, if you look at how specialized they are at hunting, you could imagine how strong their desire to hunt is. So just a small session occasionally would do wonders for their happiness and contentment, and also their love for you that you would fulfill this need for them. If you know that you have sufficiently provided for and can rule out hunger, thirst, need to pee/poop, boredom, pain, then you at least know that their fundamentals are covered. From there, you can determine if it's something else that's important, or if their behavior is actually frivolous.