Files in this Data Supplement:

• Supplemental Figure 1 -

  Fig. S1. Normalized distance from obstacle and climbing success. (A) Success is dependent on the distance from the block. The horizontal straight line distance was measured between the cockroach and the obstacle at the beginning of each climbing attempt. This was then divided by body length to normalize for individual size. Climbing attempts were categorized as success (foot reaches the top of the obstacle) or miss (foot does not reach the top of the obstacle). The data from 88 steps by 58 individuals are represented as a histogram. The distance from the obstacle for successful attempts is significantly less than that for unsuccessful attempts (P<0.0001, GEE). Statistics were preformed on raw data.

• Supplemental Figure 2 -

  Fig. S2. Antennae sample the same space regardless of lighting. Naïve cockroaches were placed in the empty arena (A,B) or in the arena when a block obstacle was present (C,D). Vertical movements of the antenna ipsilateral to the camera (occurring prior to antennal contact with the block when it was present in the arena) were digitized. To calculate y the antennal movements were divided into 5 deg. bins (x). The proportion of each trial represented by a given bin was calculated. These proportions were then added together. This gives an approximation of the amount of time spent in a given region of space. No significant differences were found between the means or variances of treatment groups (ANOVA). Means and standard deviations (s.d.) are as follows: empty arena light, mean=179.6 deg., s.d=46.3 deg.; block light, mean=172.7 deg., s.d.=38.9 deg.; empty arena dark, mean=173.1 deg., s.d=26.8 deg.; block dark, mean=175.3 deg., s.d=26.1 deg. Certain means appear to not be where one would expect because of the skewness of this data (illustrated here). The circular means are represented by the dotted line.