Flight Crew reported a family of Canadian Geese on the runway during landing rollout.

Narrative

On the landing rollout in ZZZ; landing Runway XX; I saw a family of geese come out of the grass between the runway and taxiway. We were in the process of slowing to exit the Runway. The geese were initially moving from west to east across the runway but then turned north as they saw the airplane coming. I maneuvered the aircraft nose wheel slightly to the right of centerline to not hit the geese with the nose gear and I saw the geese go by down the left side of the airplane. They were all still on the ground at that time. I never saw them attempting to fly. I would estimate our speed as being around 50 kts. as we passed the geese and slowing.I notified Tower of the geese on the runway and that we might have struck them. We turned off the runway and turned south on [taxiway] to the gate. On the way past I could see at least 2 geese still on the runway just south of [taxiway]. We taxied to the gate. I did a thorough post flight inspection of the aircraft. I could not identify where on the aircraft we struck the geese. I notified Maintenance and Maintenance Personnel came and checked the aircraft as well and could not find signs of the bird strike. Airport Operations came to the aircraft and I spoke with them. They informed me that there were 4 geese found deceased on the Runway X full grown and 2 babies. One of the operations personnel was surprised by the lack of blood on the geese. I informed ZZZ Ground that we had observed no damage on the aircraft.