What are the animals in the pen called?
The animals are zebras.
    src        edge_attr  dst
0     0               of    4
1     0  to the right of    7
2     0  to the right of   16
3     1   to the left of   15
4     1  to the right of   12
..  ...              ...  ...
75   19   to the left of    6
76   19   to the left of   15
77   19   to the left of    9
78   19   to the left of   11
79   19   to the left of   17

[80 rows x 3 columns]