Why Babies shouldn't eat honey
http://kidshealth.org/parent/infections/bacterial_viral/botulism.html
The Clostridia bacteria found in the typical environment can easily contaminate honey. As Baby bacteria flora is different than adult bacterial flora, they have not a fully matured immune system. This makes them susceptible to botulism poisoning. (Honey is a source of clostridium botulinum spores, and ingestion makes them part of th intestinal flora).
Botulism poisoning basically works by blocking neurotransmitter release from motor neurons.