The honeybit reaction is an elegant destructive-read memory cell used by Brice Due in his OTCA metapixel. It involves a glider colliding with a beehive (hence the name "honeybit"), that converts it to a block and pond. The beehive can be thought of as a value of "0" stored in the memory unit, and the block and pond constellation is a "1". A passing LWSS can then test for the presence of the pond. If a collision occurs, the LWSS and the honeybit constellation are mutually annihilated and the memory cell is restored to its "0" state, with only the original beehive remaining.
If the pond is not present, the LWSS passes by the beehive without affecting it. This means that a test input has an output (the LWSS) for the "0" case, but not for the "1" case. For an example of an alternative memory cell mechanism with both "0" and "1" outputs, see demultiplexer.
As a HWSS eater
The honey bit is also an interesting eater for an HWSS, as shown below. On the opposite side from the LWSS input path, an HWSS colliding with the block and pond constellation also happens to create the honeybit beehive, plus the exact same reset glider used in the above memory unit.