Cluster identification of ultra-wideband propagations is of great significance to the parameters extraction and measurement analysis of channel modeling. In this paper, we address this challenging problem within a promising biological processing framework. Both the two large-scale characteristics of each multipath component, i.e. the decaying amplitude and the time of arrivals (ToAs), are combined organically and explored fully in the suggested cluster identification algorithm. Each resolvable trajectory component is firstly projected onto a two dimensional (2-D) amplitude-time plane, and further modeled as a virtual ant-agent which can move around in this 2-D workspace with a preference to the high local-environment similarity. By establishing a subtle population similarity and specifying an efficient position adaptation strategy, cluster identifications can be realized by the biological ant colony clustering procedure. Owing to the population-based intelligence and the involved positive-feedback collaboration during the agents evolution, the suggested algorithm can accurately and efficiently identify the involved multiple clusters in a completely automatic manner. Experiments on UWB channels validate the proposed method. The practical parameters configuration is analyzed and a group of numerical performance metrics are derived. As demonstrated by numerical investigations, multiple clusters involved in UWB channel impulse responses (CIRs) can be extracted automatically.