This paper proposes that the observed surplus in GLMZ's child population is attributable to unregistered migration from neighboring city-states, with children traveling through interstitial territories — including Behemoth-active zones — either alone or in small, self-organized groups. The hypothesis is grounded in the well-documented phenomenon of child migration in resource-scarce urban environments, adapted to the specific geographic and logistical conditions of the Great Lakes Megalopolis Zone.

We mapped the earliest surveillance identification points for 847 unregistered children against known transit corridors, rail infrastructure, and Behemoth patrol routes. The correlation coefficient between arrival clusters and active corridor endpoints is 0.67, which we characterize as suggestive. Children appear most frequently in districts adjacent to the southern and eastern transit approaches — consistent with arrivals from the direction of the Indiana Reclamation Zone and the Detroit Autonomous Collective. Arrival timing shows loose correlation with seasonal patterns in Behemoth migratory behavior, suggesting children may be timing their travel to windows of reduced autonomous machine activity.

However, several features of the data resist this explanation. Approximately 19% of arrival clusters are concentrated in the northern Shelf districts, oriented toward Lake Michigan and the Wisconsin lakeshore — a direction from which no significant population center exists within 200 kilometers. The nearest settlement of any size is the Sturgeon Bay outpost, population approximately 400, which has not reported any child emigration. Children arriving from this direction would have to traverse open lakeshore territory with no infrastructure, no shelter, and significant Behemoth presence. Survival would require resources and knowledge that six-year-olds do not typically possess.

Additionally, interviews with children who were willing to speak about their origins produced contradictory accounts. Some described other cities in terms consistent with known settlements. Others described places that don't correspond to any mapped location. Three children described the same place — a "white building where it was always quiet" — but placed it in three different directions from GLMZ. Whether these are genuine memories, confabulations, or something else entirely remains undetermined.

We present this hypothesis as the most parsimonious explanation for the majority of the demographic surplus, while acknowledging that it cannot account for the full scope of the anomaly. Supplementary explanations are almost certainly required. We recommend cross-referencing our arrival data with census discrepancies reported by other GLMZ city-states.