What animal is walking on the grass?
The birds are walking on the grass.
    src        edge_attr  dst
0     0   to the left of    9
1     0   to the left of    5
2     1  to the right of    5
3     2   to the left of    5
4     2   to the left of    9
5     2       walking on    4
6     5  to the right of    2
7     5   to the left of    1
8     5  to the right of    0
9     5   to the left of    6
10    6  to the right of    5
11    6  to the right of   10
12    7    surrounded by    8
13    8      surrounding    7
14    9   to the left of   10
15    9  to the right of    2
16    9  to the right of    0
17   10  to the right of    9
18   10   to the left of    6