NPCs composing that spawngroup :

death_beetle (10%)

lava_beetle (30%)

lava_beetle (30%)

lava_beetle (30%)

NPCs spawning around that spawngroup :
(Max range : 200)

soldungb-Overseer_of_Air00, range=93 (-652,-62,-105)

soldungb_31, range=107 (-698,-237,-68)

sonic_bat (25%)
sonic_bat (25%)
sonic_bat (25%)
sonic_bat (25%)

soldungb_30, range=115 (-762,-237,-75)

lava_duct_crawler (50%)
noxious_spider (50%)

soldungb_28, range=94 (-677,-218,-81)

sonic_bat (50%)
sonic_bat (50%)
sonic_bat (50%)
sonic_bat (50%)

soldungb_24, range=183 (-656,-305,-66)

soldungb_20, range=194 (-595,-286,-69)

Solusek_kobold (100%)

soldungb_16, range=155 (-603,-240,-79)

soldungb_15, range=128 (-595,-179,-90)

soldungb_13, range=156 (-647,-272,-81)

soldungb_11, range=165 (-551,-159,-93)

greater_kobold (50%)
greater_kobold (50%)

soldungb_10, range=158 (-557,-108,-90)

soldungb_7, range=162 (-581,-224,-73)

soldungb_47, range=146 (-595,-46,-107)

sonic_bat (50%)
sonic_bat (50%)

soldungb_48, range=10 (-706,-124,-78)

soldungb_49, range=123 (-594,-103,-98)

sonic_bat (33%)
sonic_bat (33%)
sonic_bat (34%)

soldungb_50, range=47 (-696,-87,-100)

sonic_bat (50%)
sonic_bat (50%)

soldungb_51, range=26 (-726,-155,-91)

lava_beetle (100%)

soldungb_52, range=9 (-712,-140,-78)

soldungb_53, range=85 (-751,-208,-68)

sonic_bat (33%)
sonic_bat (33%)
sonic_bat (34%)

soldungb_56, range=146 (-569,-110,-90)

soldungb_65, range=195 (-895,-205,-78)

lava_duct_crawler (50%)
lava_duct_crawler (50%)

soldungb_68, range=168 (-877,-173,-79)

soldungb_82, range=104 (-688,-30,-105)

sonic_bat (33%)
sonic_bat (33%)
sonic_bat (34%)