The space between the sliding glass doors, and in the middle of the window frame and walls can be the reason for insects in your house. To seal the space between the sliding doors, use rubber pads or a thinly rolled newspaper. For sealing spaces between the window frames and the walls, use duct tape. Attach draft stoppers below the doors. Ina nutshell block every inch of space that can invite a bug inside the house.
If you notice bugs inside the house when you have successfully closed all drafts, kill the bugs inside. Use organic and safe methods to kill the bugs if possible. If they don’t work use a bug killer spray as your last resort.
Once all the bugs are dead, clean the house and keep the windows and door shut tight for a day. If you notice bugs, then either there is a pest infestation inside the house or they could be coming in from a draft that you don’t know of. Figure out where the bugs are coming from to deal with the problem effectually.
The entry of many pests can be stopped easily by using screens on openings such as doors and windows. Install screens on windows that you open often. However small insects such as aphids can come through the screens. If you are facing an aphid infestation problem then you might have to close the windows and doors completely.