Tidal streams are promising candidates for studying dark matter subhalos at their smallest predicted scales. This is crucial to testing CDM and understanding the nature of dark matter. Studies have proposed that tidal streams are disrupted by interactions with dark matter subhalos, causing clumpy tidal debris and gaps in the stellar distribution (e.g. Siegal-Gaskins & Valluri, 2008). We test this notion using two populations of simulated tidal streams: the first group develops in the standard FIRE-2 environment around Milky Way-mass galaxies with dark substructure. The second group’s stellar orbits are integrated in a smooth potential model of the same galaxies (which smooths over any dark subhalos present in the first case).We compare the density profiles of the two populations using a proposed gappiness statistic, 𝜎, which is sensitive to a combination of the number of local minima and the density field curvature at each minimum. We find that gaps in tidal streams can develop in both cases. Additionally, streams that develop in the smooth potential model are not universally less gappy (lower 𝜎) than those that develop in the environment with dark substructure. We hypothesize that gaps are instead caused by reduced tidal stripping at progenitor apogee, or by epicyclic motion of stars (e.g. Kupper et al., 2009), and encourage further research to test these hypotheses.