Repeat when you have reached the end of the area. Do your initial searches in any warm areas - up against walls, anywhere where it will get nice and toasty from the sun, even on a cooler day. If there is any way out, no matter how small or squished it takes to do it, do it. Offices present unique opportunities for driving your keepers mad with grief, anxiety and the possibility of becoming abruptly unemployed. Desks have wonderful obscure dark little ledges to lay on which requires a human to grovel on their knees to check out.
Office equipment offers unique places in which to hide - nice and cozy and often warm.
Even if you have just had your nails clipped, many wall coverings offer excellent opportunities for climbing one form of the corporate ladder. Some are made with interesting materials like peg board. Given the right angle, feel free to do some free-climbing up the apparently unscalable slick horizontal sides of book cases and cabinets. As ye can squish, so can ye inflate. Book cases are also very nice.