Pholcus phalangioides cellar spiders solve a prey capture problem differently across repeated trials

When animals encounter a problem they may use solutions that are innate, learned previously, learned de novo , or insightful. These solution types have distinct patterns of variation between and within individuals that can be used to test hypotheses about how animals solve problems. For instance: Innate solutions should show relatively little qualitative variation, whereas learned and insightful solutions should show increasingly higher levels of qualitative variation. We used this variation-based framework to investigate how Pholcus phalangioides spiders solve a difficult prey capture problem – capturing multiple prey that arrive on the spider’s web simultaneously. We found that the spiders used several qualitatively different solutions and did not repeat nor improve the solution across trials. These patterns of variation align closest to the predictions from the insight hypothesis, suggesting that these spiders may use insight to approach the problem of capturing multiple prey. There are, however, several limitations in our experiment that keep these conclusions somewhat speculative. This work shows the utility of using a variation-based framework for testing hypotheses regarding animal problem solving.