Are the animals dogs?
No, there are both dogs and cows.
   src        edge_attr  dst
0    0   to the left of    7
1    1   to the left of    5
2    4               on    3
3    5  to the right of    1
4    6  to the right of    7
5    7   to the left of    6
6    7  to the right of    0