Many traits, especially behavioral traits, can be repeatedly expressed within individuals over short time periods. Such traits exhibit intra-individual variation. For long considered as a noise in behavioral ecology, intra-individual variation may arise as a plasticity to changing environments or exist because intraindividual variation itself enhances fitness. Here, we report the discovery of a remarkable flexibility in the escape behaviors of Idotea ochotensis. We discovered that individuals exhibit four distinct escape behaviors: “Tonic immobility”, “Swim-immobility”, “Shrinking”, and “Swim-fleeing”. We recorded the behaviors 1375 times from 86 individuals by repeatedly assessing both microhabitat choice and escape behavior of individuals collected from two different habitats: boulders and seagrass. This study found that the intra-individual variation was greater in individuals from the seagrass habitat than in those from the boulders. Individuals from boulders consistently exhibited tonic immobility more often, while individuals from seagrass exhibited a greater flexibility in multiple behaviors. This discovery offers a potential avenue to illuminate how intra-individual variation in escape behavior can be advantageous in the context of predator avoidance.