Honeybees do not like to leave the hive in bad weather.
They prefer to remain safe inside, but if the bees must exit, they only go out for a short trip, and carry small pebbles to weigh down and balance themselves.
191 vērō: “in truth,” adverb.
191 pluviā impendente: ablative absolute (AG 420).
192 longius: “too far.”
192 crēdunt:crēdo takes a dative object, here caelō.
192 adventantibus Eurīs: ablative absolute (AG 420); Eurus is the east wind, which brings rain. It is often thought to be unlucky.
193 circum: “all around,” adverb.
194 brevēs: accusative plural masculine, modifying excursūs.
194-196 saepe lapillōs…tollunt: honeybees do not actually carry ballast to weigh themselves down, though they will carry certain things (for example, corpses) out of the hive. Other bees, such as mason bees, do occasionally carry materials. Vergil seems to have taken this idea from previous writers, probably originating with Aristotle (HA 9.40).
195 ut…saburram: a simile, comparing the bees to small boats.
195 flūctū iactante: ablative absolute (AG 420).
196 tollunt: take as the verb with both the implied bees in line 194 and cumbae in 195.
196 hīs: supply lapillīs; ablative of means (AG 409).