Make a 1 high 2 wide hole. Wait on the other end and the spider will go through. No other mob can, except for silverfish.
I don't think silverfish spawn naturally,I think they spawn in strongholds(spawner+silverfish blocks)or do they?But anyways just make a 1 high and 2-as much blocks wide as you want for spiders to spawn.
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Here's your solution. The ceiling does still need to be made of glass or other transparent blocks, but if you do that, then only spiders will be able to spawn.
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