Trace fossils tell us:
 

• how sedimentary structures are produced by living organism which is then preserved in the rock record
• about an organism's reaction to the environment; thus interpretations can be made of the primary environment with respect to  deposition rates, salinity levels, aerobic and anaerobic conditions, chemical variations, temperature fluctuations, and abundance of nutrients
• about the feeding strategies, style/speed of movement, and evolution of the organism
• about the biocenosis of a facies or environment
• how environments of the past, with respect to physical energy, are similar to environments of the present due to the possible recurrence of similar trace fossils over time
• how physical energy of the environment effects an organism because the energy affects the grain size of sediments, substrate stability, and food availability (either in suspension or deposition)
• about a rock unit or a regional unit, with respect to their facies or sub facies because a uniform likeness of trace fossils may be found within these facies