The term "be heads" doesn't represent a common word or phrase in English language. However, if we consider the words "be" and "heads" separately, we can look at their antonyms. The antonym for "be" would be "not be" or "be absent," while the antonym for "heads" could be "tails," "foot," or "bottom." Depending on the context in which these words are used, their antonyms may also vary. It's always important to understand the meaning and usage of a word before trying to identify its antonyms.