got this from parenting.ivillage.com
Honey is not safe for babies under the age of one.
Honey can harbor the botulinum spore. This spore, under the right conditions, can grow and give off a deadly toxin. The spore is inhibited from growing in environments of high acidity. The acidity of an infant's digestive system is not high enough to prevent the growth of the spore. By the time a baby is one year old, stomach acidity has risen closer to that of an adults, and is at a level that would inhibit the growth of the spore.
and this one from kidhealth
It's true that honey should not be fed to infants younger than 1 year old. Clostridium bacteria that cause infant botulism usually thrive in soil and dust. However, they can also contaminate certain foods — honey in particular. Infant botulism can cause muscle weakness, with signs like poor sucking, a weak cry, constipation, and an overall decreased muscle tone (floppiness).
Parents can reduce the risk of infant botulism by not introducing honey into their baby's diet until after the first birthday. As kids get older, their bodies are better able to handle the bacteria.
and this's from healthgood
Feeding honey to your baby could be harmful if he or she is younger than 12 months of age. Honey could be the cause of a rare type of food poisoning called infant botulism--a serious, even deadly, illness. Honey is the food most commonly found to contain the bacteria causing botulism. The American Academy of Pediatrics advises that honey should not be added to the food, water, or formula that is fed to infants younger than 12 months of age. This recommendation includes foods processed with honey.
Honey is a known source of bacterial spores called Clostridium botulinum that produce a toxin which can cause infant botulism. These spores can also be found in soil, water, uncooked food, and even household dust. Infant botulism can occur from breathing in vacuum cleaner dust, but eating honey is the number one preventable cause. While honey is safe for infants over 12 months of age, infants under 12 months of age have not yet developed beneficial bacteria in their digestive tracts that can control botulism spores. Therefore, do not add honey to baby food, water, formula, or medicine. Do not dip a baby's pacifier in honey. Even the honey in some processed foods can cause this problem. After an infant eats the spores of this bacteria, the disease can occur within a few hours or up to a week after the exposure.
Symptoms of infant botulism include weakness in the neck, arms, or legs; inability to suck or cry normally; inability to feed or swallow; and persistent constipation. The first symptom is constipation, which can appear three to 30 days following ingestion of honey. The next symptoms observed are listlessness, decreased appetite, and a weakened cry over the next several days. Gagging and sucking reflexes diminish and the child moves less and less. Infant botulism frequently causes an infant to have an unusual breathing pattern, which often requires putting the infant on a ventilator to help with breathing.
Most infants recover from botulism with hospital care. However, if infant botulism is not treated immediately, it could result in death. Hospital care is necessary. Identifying the botulism toxin in the stool is needed for proper diagnosis. This toxin can cause nerve damage for weeks or even months. Neither antibiotics nor antitoxin have proven beneficial in treating infant botulism and may even make the illness worse. There is also a link between infant botulism and SIDS (sudden infant death syndrome), because breathing is affected in the most severe stages of the illness. It is believed to be the cause of death in 10% of SIDS cases. As children get older, the stomach acid, bacteria, and the intestinal tract mature to make them less susceptible to the toxins that botulism spores produce. The single most effective way to prevent infant botulism is to avoid giving honey to infants younger than 12 months of age.