\input fmt/com.h \input fmt/font.h \input tables.i \definecolor{page}{rgb}{.87,.95,.85} \definecolor{text}{rgb}{0,0,0} \definecolor{trim}{rgb}{0,0,.50} \pagecolor{page} \color{text} \nopagenumbers \emergencystretch=.1in \pdfpagewidth=14in \pdfpageheight=8.5in % config \newdimen\margin \margin=.25in \newdimen\titlesize \titlesize=.66in \newdimen\textheight \newdimen\fullhsize \fullhsize=\pdfpagewidth \advance\fullhsize by -2\margin \vsize=\pdfpageheight \advance\vsize by -2\margin \hoffset=-1in\voffset=-1in \advance\hoffset by \margin \advance\voffset by \margin % 0 margin \topskip=0pt %calculate textheight \textheight=\vsize \advance\textheight by -\titlesize \advance\textheight by -5pt \divide\textheight by 2 \spacing=100 \parskip=0pt \font\title=cmr10 at 18pt \font\text=cmr10 at 13pt \font\bold=cmb10 at 13pt \font\cap=cmr10 at 8.5pt \text \adjs \let\bf\bold \hsize=6.3in \def\pic#1#2{\pdfximage width #1{#2}\pdfrefximage\pdflastximage} \def\picturetop#1#2#3{\vtop{\pic{#3}{#1}\hsize=#3\caption{#2}}} \def\tabrule{\noalign{{\color{trim}\hrule}}} \def\centering{\leftskip0pt plus 1fil\rightskip\leftskip \parindent0pt\parfillskip0pt} \newcount\ct\ct=0 \def\li{\global\advance\ct by 1\par\pre{\number\ct.}} \newcount\cct\cct=0 \def\alph{\ifcase\cct\or a\or b\or c\fi} \def\lli{\global\advance\cct by 1\par\pre{\alph.}} \halign to \fullhsize{\tabskip0pt plus 1fil{\color{trim}\vrule}#&\vtop to \textheight{#}&{\color{trim}\vrule}#&\vtop to \textheight{#}&{\color{trim}\vrule}#\tabskip0pt\cr\tabrule &\multispan{3}\hfil\vbox to \titlesize{\hsize=2\hsize\centering\vfil {\title Antlion Herding Patterns with Interrupted Communication Pathways} \vfil Holden Rohrer and Radeen Abree, Centennial High School, Roswell, Georgia, US. \vfil}\hfil&\cr\tabrule &%#1 \vskip1pt \vbox to 0pt{\pic{1.5in}{img/2019-10-18-1.jpg}\vss} \hangindent=1.55in\hangafter=-1\parindent0pt \noindent{\bf Rationale:}\par \hangindent=1.55in\hangafter=-5\parindent0pt \input src/rationale.i \input src/hypo2.i &&%#3 \cap \def\wid{1.9in} \vfil \line{\hfil\vbox{\picturetop{graph/boxplot.png}{This boxplot illustrates the nearest neighbor metric on different trial sizes and interventions. The artificial pits trials showed the largest impact on the metric, indicating antlions choose settlement based on surrounding pits.}{\wid}}\hfil \hbox{\picturetop{imgs/obstacles-24x24.png}{Voronoi diagrams show territory that is nearest to a given pit. Blue dots represent pits, and colored shapes represent obstructions.}{\wid}}\hfil \hbox{\picturetop{imgs/trails-24x24.png}{Trail erasure did not interrupt, and may have reinforced, the regularized pattern antlions make. Food-catching regions are well-distributed between pits in all trials.}{\wid}\hfil}}% \vfil \line{\hfil\stats{Pit depths and widths remained fairly constant between trials. The nearest-neighbor metric also remained constant, but only within trial sizes. This indicates antlions respond to their environmental restrictions.}\hfil}% \vfil &\cr\tabrule &%#2 \smallskip \advance\ct by 1\pre{\number\ct.} 24 16oz deli containers were acquired and 1 antlion was placed in each \li The sand (100lbs) was uniformly spread into a $24"\times24"$ plastic container \li Marks were made on the box so the pits’ locations could be observed. \li Each trial was started by introducing a constant number of antlions, at the same time \li After the first and second days of each two-day trial, the coordinate locations, diameters, and depths of each antlion pit were recorded for analysis. \li After each trial, all living antlions were restored to their pits and dead antlions disposed of. \li Further trials repeated these same protocols except with space restrictions of $24"\times24"$ and $12"\times12"$ and three disruption methods: \leftskip.3in \lli ``Trail erasure'' included brushing away old trails in the sand that antlions have dugout, in an effort to determine if the antlions are reliant upon the presence of trials or pheromones when distributing. \lli ``Fake pits'' were introduced to mimic an antlion pit, in order to determine if antlions were dependent on the presence of surrounding pits. \lli ``Artificial obstacles'' included the introduction of rocks to determine if antlions are aware of the shape of their settlement region and use that to organize the group. \smallskip &&%#4 \smallskip This experiment investigated how antlions make individual settlement choices, and how those choices create group patterns. Environmental factors, in terms of other pits, trails, and environment shape were investigated. Antlion larvae were shown to regularly, rather than randomly, distribute themselves, indicating they avoid other pits and respond to environmental structure. As also observed in the previous study, antlions use behaviors like this, cannibalism, and reclusivity as mechanisms to limit intra-species competition. These behaviors increase species fitness and therefore are an evolutionary advantage. Avoidance mechanisms can be extended to the analysis of other animals and engineering applications. Bottom-up organization often relies on a hierarchical image of its members, like a hexagonal or rectangular grid, but individuals don't require strict communication pathways for efficient, semi-regular distributions such as an antlion's. The distribution patterns of the antlions can also be expanded to understand similar organisms, such as termites, ant, bees, and wasps, as these animals also distribute as groups. Similar behaviors may be used to draw conclusions regarding the evolutionary history of these organisms. \smallskip &\cr\tabrule} \bye