To enhance both the sensing and covert communication performance, a dual-unmanned aerial vehicle (UAV)-aided scheme is proposed for integrated sensing and communication networks, in which one UAV maneuvers as the aerial dual-functional base-station (BS), while another UAV flies as the cooperative jammer. Artificial noise (AN) transmitted by the jamming UAV is utilized not only to confuse the ground warden but also to aid the aerial BS to sense multiple ground targets by combing the target-echoed dual-functional waveform and AN components from a perspective of the hybrid monostatitc-bistatic radar. We employ the distance-normalized beampattern sum-gain to measure the sensing performance. To maximize the average covert rate (ACR) from the aerial BS to the ground user, the dual-functional BS beamforming, jamming UAV beamforming, and dual-UAV trajectory are co-designed, subject to transmit power budgets, UAV maneuver constraint, covertness requirement, and sensing performance constraint. The imperfect successive interference cancellation (SIC) effects on the received signal-to-interference-plus-noise ratio are also considered in maximizing the ACR. To tackle the highly complicated non-convex ACR maximization problem, dual-UAV beamforming and dual-UAV trajectory are optimized in a block coordinate descent way using the trust-region successive convex approximation and semidefinite relaxation. To find the dual-UAV maneuver locations suitable for sensing the ground targets, we first optimize the dual-UAV trajectory for the covert communication purpose only and then solve a weighted distance minimization problem for the covert communication and sensing purpose.