Real-world networks such as social and communication networks are too large to be observed entirely. Such networks are often partially observed such that network size, network topology, and nodes of the original network are unknown. In this paper we formalize the Adaptive Graph Exploring problem. We assume that we are given an incomplete snapshot of a large network and additional nodes can be discovered by querying nodes in the currently observed network. The goal of this problem is to maximize the number of observed nodes within a given query budget. Querying which set of nodes maximizes the size of the observed network? We formulate this problem as an exploration-exploitation problem and propose iKNN-UCB, a novel nonparametric multi-arm bandit (MAB) algorithm for determining which nodes to be queried in an adaptive manner. Using synthetic networks and real-world networks from different domains, we demonstrate that our proposed algorithm discovers up to 40% more nodes compared to existing state-of-the-art algorithms.