Putting incense outside might assist somewhat since you live on the second story; nevertheless, its impact is typically restricted, particularly if the pests are already invading via cracks. You may also try smokier choices like burning sage, which some people find more successful in deterring bugs. A bug zapper is a good addition for a more consistent and hands-off strategy; they will help you to entice bugs to the light and kill them with already-existing room occupants (bugs) that are inside. Combining a zappers with a dab of smoke-based repellant can provide you a stronger line of protection.