Aggregations and Burrowing.

<p>(<b>A</b>) Larvae exhibited greater aggregation behavior on harder substrates than on standard or soft substrates (N = 12 each), and (<b>B</b>) aggregated more at sites where the surface had been broken with an artificial “trench” (see methods, N = 7) than sites that had no trenches (N = 6) or a trench in all quadrats (N = 7). Note that even when food was uniformly soft or trenched at every quadrat, larvae still showed significant aggregation. Additionally, (<b>C</b>) when we manipulated the number of larvae per dish, larvae in larger groups started burrowing sooner than larvae in smaller groups (N = 6).</p

An example dish showing typical larval aggregation and movement behavior starting with a uniform egg distribution.

<p>Larvae are highly mobile and form modest aggregations that move over time. This dish was chosen because its aggregation index was closest to the median. Quadrat color represents the number of larvae per quadrat.</p

Detailed Behavioral Observations.

<p>We monitored two foraging larvae for ten minutes twice per day from hatching until pupation (N = 10 pairs). Larval social interactions, as measured by time observed within 5 mm of each other (thin solid line), and the time spent physically touching one another (dashed line) increased, then declined at 70 h post hatching. The proportion of time that larvae spent burrowing into the food (thick solid line) increased steadily to almost 1, before declining prior to pupation.</p