I live in a mid-rise building, and check my screens. They're about as secure as a screen can get. the frame that hold them in allows them to slide up and down, but they're almost immovable otherwise. I check them every so often, usually when I open them for the first time in the season.
Many years ago, my dad replaced all the nasty ancient windows in their house with casement windows. I hate casement windows. At least those ones. the screens are held on by little swingable (and screwed down, so they can be loosened over time) tabs. Now, there is actually a funny story with those screens. Skunk, our now aptly titled Senior Citizen, had a best friend, Smoky. Smoky came to us soon after most of Skunky's littermates (who all adopted our family as a group) had wandered away or been killed (one by car, one by snacking on a poisoned gopher, one abducted by a cat-lady who refused to let him outside again). (My parents' attitude about pets being indoor vs outdoor is different than mine)
Smoky was a little furry ham. Our house was all one story, raised a little off the ground by a partially exposed crawlspace. Smoky discovered that when i left a particular window in my room open (one that was just over the front porch steps- so the distance was shorter), she could jump up, grab on with her claws and promptly wedge herself in the window. Sometimes I was in my room and saw her do this, sometimes I would walk into the room and hear this 'mrroowww!!' coming from my window just as i walked inside. She startled me on many, many occasions with her little trick. I mentioned those tabs that hold the screens in because at least once, she jumped up and discovered the tabs weren't holding like they should. Smoky is no longer with us, sadly. She passed away in 2000. She was about 10 years old.
Then another screen incident. CoCo, a kitten my sister found abandoned next to the coke machine in a general break room at her office building in 2003. Tiny, black and very freaky. Also, very intelligent. She was able to outsmart my father, which is amusing in itself. CoCo discovered she could make the screen door move if she stuck her claws into it. Skunk and Max (short for Maximus... guess what year we adopted him?) soon caught on, but only to watch her as she learned how to open the screen door. According to my dad, she'd sit at the stoop, make sure no one was in the living room, and claw the door about half an inch. It's an old aluminum screen and frame, so it makes noise. Then she'd move it a little more. stop and check, move some more. when the opening was big enough for them to nose their way through, Skunk and Max would barge right past her and push their way through. then CoCo would join them. My dad was usually sitting at his desk or in the kitchen when this happened, and all of a sudden he'd feel something furry brush against his legs. He's 78 years old, a fright like that is not too good for him.
He attached a hook latch way up high on the screen on the inside, so this doesn't happen anymore. I kinda wish he'd let it happen. The stories are always amusing.
(BC: Before Coffee)