Some warning signs of breadcrumbing are sporadic communication, hesitancy to make plans, and avoiding discussing or clarifying the relationship's nature. There are also inconsistencies in expressions of love or interest. Key red flags for identifying breadcrumbing include: 1. Frequent unkept promises. 2. Mixed signals in their behavior. 3. Consistent unavailability and busyness. 4. Selective interest, mainly when it suits them. 5. An avoidance of discussing future plans or commitments.