A new study describes why a child dislikes the bad taste of medicine.
Philadelphia researchers found that children are born with a much stronger preference for sweet flavors that continues through their teen years.
The problem is humans have more taste receptors for bitterness than sweetness.
The flavor of some medications is already masked, but it's difficult to mask the truly bitter liquid medicines.
Researchers hope the study can help find ways of overcoming these unpleasant flavors.