Antonyms for "bump heads" can be understood in terms of cooperation, harmony, and agreement. Instead of "bump heads," people can "mingle thoughts" and "collaborate ideas" to reach a common ground. Alternatively, they can "see eye to eye" and "fall in line" with each other's views. Another antonym can be "smooth collaboration," where all parties involved work together smoothly and without any disagreement. Using "work together" or "synergy" instead of "bump heads" in a sentence can communicate a sense of teamwork and positivity. In the end, the choice of words is essential in conveying the right message and fostering a good working relationship.