fun minecraft mod you may not know about, or more importantly may not know exactly -all- that it does
Scarecrows' Territory states in it's description that it "allows you to keep spawners activated and keeps mobs spawning when there are no players around!"
there's that last bit that had me squinting a bit over. further down it's bullet points list
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The Scarecrow keeps spawners in an 8 block radius activated
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The Scarecrow allows passive mob spawning in an 8 block radius
i honestly don't care about spawners or passive mob spawning, but what's interesting is that in the changelog it lists:
Mobs will now exclusively spawn within the range of the scarecrow.
which is exactly what i want, what i've been wanting forever since i've seen the bots you can create in Carpet Mod, a "fake player" solution to hostile mob spawning. the long and short of how hostile mob spawning works is it has to be dark, the block a mob attempts to spawn on can't be too close, and it can't be too far

anyway, here's an example of how effective the scarecrows are in a not at all optimized mob farm:
the purple thing at the top is just used to keep bats from spawning, and the mobs are simply pushed with the Create mod fans.
im amazed that more advertising isn't being done on how this thing allows for mobs to spawn without a player being in range. in fact if it's dark and you plop down a scarecrow mobs will spawn just right up next to you. the biggest bugbear i have with minecraft mechanics as a whole is that they require a player to be in range for mob spawning, and have a player to be in range for random ticks to affect a litany of things you would just want to be happening always (crop growth, dripstone lava filling cauldrons, amethyst cluster growing)
luckily the same mod author also has their own version of chunk loaders, which unlike every other implementation of chunk loaders (or at least they never advertised that they had this feature) will continue to process random ticks, thus allowing your various farms to not be in stasis when you leave the area:
that's all, just a couple of really handy mods i think more people should be using.
