Biologists rely heavily on visual representations to teach and communicate science. In a typical introductory biology textbook over half of all figures contain arrows, used in dozens of different ways. We find that there is little consistency or clarity in how arrows are used to explain concepts, especially across different subfields of biology. This results in confusion for students, and likely acts as a barrier to learning. We are working with professional illustrators and editors to define a set of principles to bring more uniformity and transparency to the meaning of biological figures in the future. This work could potentially impact many thousands of students enrolled in biology courses worldwide every year.