What is the bird standing on?
The bird is standing on the rock.
   src        edge_attr  dst
0    1   to the left of    7
1    3   to the left of    7
2    4      standing on    5
3    4   to the left of    8
4    7  to the right of    3
5    7  to the right of    1
6    8  to the right of    4