What animal is the dirt on?
The dirt is on the zebra.
    src        edge_attr  dst
0     1   to the left of    5
1     3   to the left of    7
2     3  to the right of    9
3     4  to the right of   16
4     5  to the right of    1
5     7  to the right of    9
6     7  to the right of    3
7     8  to the right of   12
8     8               on   17
9     8  to the right of   14
10    9   to the left of    7
11    9   to the left of    3
12   12   to the left of    8
13   14   to the left of    8
14   15               of    5
15   16   to the left of    4