I understand why spiders are spawning in here, I just haven't gotten to fixing it yet. The thing that I don't understand is why skeletons and zombies are able to spawn. I followed the tutorial correctly, but I thought the trapdoors would keep any other mobs from spawning. Is it the type of trapdoor? I was told it doesn't matter what kind I used along as I placed them correctly.
You have an extra block of space between each platform (the block the water flows when flushing the platform, the air block at head height above that, and the block the trapdoor occupies), which means you've got somewhere around 2.75 blocks of space to fit a mob. Creepers, spiders (because you hadn't spiderproofed yet), skeletons, and zombies all come in below this height and so are able to spawn.
rebuild the platforms. You need to have only 2 blocks of space between each platform. The trapdoors will be at head height on the bottom of the next platform up, which means as a player you can't simply walk onto the platform without crouching/swimming/elytra-flying. Creepers are shorter than the player (player height = skeleton height = zombie height) and the trapdoor is thin enough that creepers can still spawn on the platforms.
I understand why spiders are spawning in here, I just haven't gotten to fixing it yet. The thing that I don't understand is why skeletons and zombies are able to spawn. I followed the tutorial correctly, but I thought the trapdoors would keep any other mobs from spawning. Is it the type of trapdoor? I was told it doesn't matter what kind I used along as I placed them correctly.
You have an extra block of space between each platform (the block the water flows when flushing the platform, the air block at head height above that, and the block the trapdoor occupies), which means you've got somewhere around 2.75 blocks of space to fit a mob. Creepers, spiders (because you hadn't spiderproofed yet), skeletons, and zombies all come in below this height and so are able to spawn.
How would I fix this?
rebuild the platforms. You need to have only 2 blocks of space between each platform. The trapdoors will be at head height on the bottom of the next platform up, which means as a player you can't simply walk onto the platform without crouching/swimming/elytra-flying. Creepers are shorter than the player (player height = skeleton height = zombie height) and the trapdoor is thin enough that creepers can still spawn on the platforms.