In App + Web properties, traffic from bots and spiders is automatically excluded. This ensures that your Analytics data, to the extent possible, does not include events from known bots. At this time, you cannot disable bot traffic exclusion or see how much bot traffic was excluded.
Bot traffic is identified using a combination of Google research and the International Spiders and Bots List, maintained by the Interactive Advertising Bureau. Visit the Interactive Advertising Bureau (IAB) website for more information.