Again, the argument is frequently illustrated by observation of the habits of various animals. In these passages Lucretius shows the curiosity of a naturalist, as well as the sympathetic feeling and insight of a poet. How graphic, for instance, is his description of dogs following up the scent of their game—
Errant saepe canes itaque et vestigia quaerunt.[406]
How happily their characteristics are struck off in the line—
At levisomna canum fido cum pectore corda.[407]
The various cries and habits of birds are often observed and described, as—
Et validis cycni torrentibus ex Heliconis
Cum liquidam tollunt lugubri voce querellam;[408]
and again—
Parvus ut est cycni melior canor ille gruum quam
Clamor in aetheriis dispersus nubibus austri.[409]