A minute brown and grey creature resembling anthropomorphic insect, with four arms, four legs, big mandibles, compound eyes, and vestigial wings.
CR 1/2; XP 200
N Tiny Monstrous Humanoid
Init +2; Senses darkvision 60 ft., low-light vision; Perception +0
AC 14, touch 14, flat-footed 12 (+2 Dex, +2 size)
hp 7 (1d10+2)
Fort +2, Ref +4, Will +2
Defensive Abilities evasion
Speed 20 ft., climb 20 ft., fly 20 ft. (poor)
Melee bite +1 (1d3–2 plus 1d3 acid)
Ranged dropped brick +5 (1d4)
Space 2-1/2 ft.; Reach 0 ft.
Special Attack brick-eater, drop brick
Str 6, Dex 14, Con 14, Int 9, Wis 11, Cha 9
Base Atk +1; CMB +1; CMD 9 (13 vs. trip)
Skills Climb +6, Fly +2, Knowledge (engineering) +3, Stealth +10
Environment any urban
Organization solitary, pair, or crew (3–10)
Brick-Eater (Ex) Brick mites nibble on bricks weakening them and making them prone to falling apart, or occasionally eating whole bricks. A brick mite can take a minute to turn one 5-ft. square made of brick into a difficult terrain. A brick mite can take one hour to consume bricks within 1-ft. cube. Multiple brick mites can cause those effects proportionally faster.
Drop Brick (Ex) Brick mite often drop brick shards on creatures below it when they want to harm them.
Brick mites are dangerous pests that can infest urban areas. While not violent or particularly threatening themselves, they feast on bricks causing serious damage to buildings and other construction, often with lethal results to their denizens and users.
They seem to be descendant from some fort of insect native to elemental planes (possibly one that crossbreed with some species of gremlins), which might have feed on soft stones and clay, but by now, they are fully dependent on a diet of bricks, sun- and oven-baked. They are intelligent and can be negotiated with, but any deal negotiated with brick mites need to take into account their restricted diet and inherent voraciousness for they simply are in no position to agree to a deal that would not include some sort of supply of bricks to be eaten.