Do these animals all have the same species?
No, there are both dogs and cows.
    src        edge_attr  dst
0     0  to the right of    8
1     1   to the left of    3
2     1               of   11
3     1   to the left of    7
4     3  to the right of    1
5     3  to the right of   11
6     3  to the right of   10
7     3  to the right of   17
8     3  to the right of    9
9     3  to the right of    6
10    4               of   14
11    4   to the left of    7
12    5   to the left of   14
13    6  to the right of   17
14    6   to the left of    3
15    6   to the left of    7
16    7  to the right of    1
17    7  to the right of    6
18    7  to the right of   12
19    7  to the right of    4
20    7  to the right of   11
21    7  to the right of   15
22    7  to the right of   10
23    7  to the right of    9
24    7  to the right of   18
25    8   to the left of    0
26    9  to the right of   17
27    9   to the left of    3
28    9   to the left of    7
29   10  to the right of   17
30   10   to the left of    7
31   10   to the left of    3
32   11   to the left of    7
33   11   to the left of    3
34   12   to the left of    7
35   12   to the left of   14
36   14  to the right of   17
37   14  to the right of    5
38   14  to the right of   12
39   15   to the left of    7
40   17   to the left of    9
41   17   to the left of    6
42   17   to the left of   10
43   17   to the left of    3
44   17   to the left of   14
45   18   to the left of    7