Yes they are, according to S Kirschke, et al., Three decades of global methane sources and sinks. Nat Geosci 6, 813–823 (2013). Termites emit around 11,000,000 metric tons of methane per year. All natural sources emit 347,000,000 metric tons per year. This corresponds to 3.17%. Here is a bar char visualizing this:
A #
B ###############################
A is the emission by termites
B is the total emission by natural sources
spam fails_task lang_mismatch pii not_appropriate hate_speech sexual_content quality toxicity humor helpfulness creativity violence