Shadow Leeches Bombs are bombs used by the League of Shadows in the Bionicle Kingdom IV RPG and are used to set up the Shadow attacks that occur in Metru Nui each night. Although called bombs, they are really just sealed containers for a dozen or so Shadow Leeches that are asleep until a timer goes off to release them to steal the light of whatever is nearby at the time.
The sleep state, that leeches are in, extend how long they live and thusly they could sleep for a century and still awake to steal light from creatures. Nonetheless they die soon after the first creature that they take light from, which may have been a result of leaving them to sleep for so long.
Even with this issue, the Shadow Leeches had been able to corrupt a lot of Archives Rahi and the Rahi of streets in Metru Nui. So far, no reports have been made that any Matoran or Toa having lost their light. Although if they had, they may not look much like themselves as the Shadow Leeches from bombs have prove to not only take light from creatures nearby, but make them look and act different.
It is unknown what is causing this change in victims of Shadow Leeches attacks, so it is possible these Shadow Leeches passed on some sort of mutations to the victims by a Makuta Virus added to them. Then again, it isn't even known widely enough by the Matoran or Toa of Metru Nui that these bombs exist, so much about it is not known.
All that is really known is that a Shadow Matoran named Kraamato had set most of them up in Metru Nui to stage the so called Shadow attacks for the League. Beside that not much else is known at the moment.