You can make silent, deadly Minecraft lava traps with string

pcgamesn.com:

Minecraft lava is undoubtedly one of the worst surprises to stumble across in the sandbox game. You can be happily walking through a system of caves, just minding your own business and maybe trying to find another bunch of resources, and then bam, you’re on fire, and everything you own is gone. It’s harrowing, but after a few hours of gameplay, you can overcome that problem and even master lava and start incorporating it into your builds.

You can do a lot with lava too, like making it a cool floor feature, or using it as a way to defend your base from the hordes of monsters that can besiege you in the night. The only trouble is that the bubbling noise can be kind of annoying. However, it turns out that you can actually get rid of that without impeding the lava itself – just by using string.

This incredibly odd interaction was discovered by Reddit user Henry1691. (Judging by the username, I’m amazed Henry is playing Minecraft at the age of 331.) They put the post up showing a video of the interaction, and, well, it’s really quite odd, even as far as Minecraft goes. The usually bubbly lava becomes eerily quiet the moment it’s covered in string, and the string doesn’t even burst into flames.

It all works because lava is reliant on air blocks to work properly. Without one block of air above it, not only does lava not make sound, but it also can’t set the string on fire. As a result, you get silent lava that makes for an incredibly devious trap. The biggest issue with using lava as a pitfall normally is that it’s very easy to hear. If you just cover it in string, other players won’t be able to hear it, and you can use it as you want as long as you cover it with a Redstone mechanism of some sort, or just hide the hole for it