Hunting positions in a sit-and-wait predator

Modifying decisions depends on the cost of change, especially in sit-and-wait predators. Once situated, they should remain immobile, as position changes can disturb their traps or alert prey and predators. Antlion larvae (Myrmeleon spp.) dig conical pits in the soil to capture walking insects. The larva then ejects the prey carcass using strong, backward, pendular mandible movements. Therefore, their position on the pit influences the direction to expel carcasses and debris. We tested the hypothesis that antlion larvae orient at the bottom of their pits to avoid future movements, and that they decide their position based on environmental features such as the proximity of vertical obstacles and the ground’s slope. In the field, we dropped debris (rice grains) into pits. The expelled debris direction was consistent as larvae maintained their position at the bottom of their pit throughout time, and their position was independent of the pit's distance from a wall. In the lab, we induced lar..., We conducted two studies: one field experiment to evaluate the distance and consistency of debris expulsion direction, and a combined field and laboratory experiment to examine larvae's orientation concerning environmental features.
I. In the field, in Yucantán, México, we experimentally determined the relationship between the expelling distance and the size of the larvae, and explored their consistency in the expelling direction. At the end of the dry season (May 2023), we randomly selected 45 different-sized antlion larvae pits. We measured their pit ratio with a caliper; an established proxy of larva size. Then, we carefully dropped half of a rice grain into each pit center from 10 cm above the pit, simulating the fall of debris and stimulating larvae to clean it.
To measure the consistency of the expelling direction, we repeated rice grain trials between 3 and 7 times in each pit. The number of repetitions depended on the pit status and larvae' behavior. The time between trials was ..., # Hunting positions in a sit-and-wait predator

Dataset DOI: [10.5061/dryad.1zcrjdg5h](10.5061/dryad.1zcrjdg5h)

## Description of the data and file structure

### FILE \"consistency_field_data.csv\"

OVERALL DESCRIPTION:

This file contains the data for a field experiment in which we determined the relationship between the expelling distance and the size of the larvae, and explored their consistency in the expelling direction.

COLUMN EXPLANATION

* Pit_ID: Individual identification of each Myrmelion immaculatus antlion larva that we studied in the field in Yucatan, Mexico.

* Pit_number: Consecutive number of each larva we studied. Note: By definition, each larva had only one value for this value. Hence, \"NA\"s are included for many rows.

* Pit_Ratio: ratio of the pit, in cm. Note: By definition, each larva had only one value for this value. Hence, \"NA\"s are included for many rows.

* Trial_number: repetition for each of the trials conducted with a given larva.

* Expelling_distanc...,