why did the romans use an eagle as a symbol
Aquila (Roman) The eagle was extremely important to the Roman military, beyond merely being a symbol of a legion. A lost standard was considered an extremely grave occurrence, and the Roman military often went to great lengths to both protect a standard and to recover it if lost; for example, see the aftermath of the Battle of the Teutoburg Forest, where the Romans spent decades attempting to recover the lost standards of three legions.
Trojan Horse According to Quintus Smyrnaeus, Odysseus thought of building a great wooden horse (the horse being the emblem of Troy), hiding an elite force inside, and fooling the Trojans into wheeling the horse into the city as a trophy. Under the leadership of Epeius, the Greeks built the wooden horse in three days. Odysseus's plan called for one man to remain outside the horse; he would act as though the Greeks had abandoned him, leaving the horse as a gift for the Trojans. An inscription was engraved on the horse reading: "For their return home, the Greeks dedicate this offering to Athena". Then they burned their tents and left to Tenedos by night. Greek soldier Sinon was "abandoned", and was to signal to the Greeks by lighting a beacon.[2] In Virgil's poem, Sinon, the only volunteer for the role, successfully convinces the Trojans that he has been left behind and that the Greeks are gone. Sinon tells the Trojans that the Horse is an offering to the goddess Athena, meant to atone for the previous desecration of her temple at Troy by the Greeks, and ensure a safe journey home for the Greek fleet. Sinon tells the Trojans that the Horse was built to be too large for them to take it into their city and gain the favor of Athena for themselves.