Rashi: Birds that see small wheat kernels spread on the trap, they think that they are for free ¹ . They do not realize why they are spread; they descend and eat them. Orchos Tzadikim (Sha'ar ha'Chanifus, DH v'Yesh) - this is the way of a flatter. He speaks sweetly so his colleague relies on him.

R. Yonah: The judgment for man's deeds is depicted as a trap - everything is given on collateral; a trap is spread (Avos 3:20), "u'Farasti Alav Rishti v'Nispas bi'Metzudasi" (Yechezkel 17:20). Even though also the Rasha believes that there is judgment and a judge, when he desire to sin and covets to steal, it seems to him that the line and plumb-line of judgment are stretched for naught. I.e. his actions will not be [returned] to his bosom. Desire causes him to forget judgment and payment (for sins).

R. Yonah: They are birds. They look at the time grain in the trap. Once a person sins, he is caught in the trap, even though sometimes they delay and do not pay [his punishment] to him immediately.