Hi Derek
Given the size of the office, it may not be fleas.
I have had instances when Customer have complained of being bitten, but no obvious signs of insect activity seen. It has turned out to be a static charge
When a person moves around in an office environment, they are usually surrounded by lots of electrical equipment. Added to this is the material of the carpeting (often synthetic) and the abundance of metal-framed desks, chairs and cabinets. In short, the individual builds up a static charge on their body through actions such as shuffling along the carpet.
They then move to a metal-framed cupboard or sit at a metal-framed desk. The result of this close contact is that a charge of static electricity arcs across from the person to the desk or vice-versa.
This 'zap' or 'belt' of static feels just like an insect bite - a characteristic 'sharp' sensation, followed by itching and discomfort. Inspection of the 'bite' will often reveal the typical signs of an insect bite - a raised redness of the skin, and even a pale white centre at the site of the bite'.
BUT, there is no puncture mark (ie: no hole where biting or piercing mouthparts have broken the skin).
There is some evidence to suggest that a second phenomenon involved with static electricity may occur. In environments such as offices, filing/record rooms and document stores, there are often an abundance of very small fibres. In situations where static electricity may build up, these fibres also become charged, and thus can become 'miniature javelins'. These can embed themselves in the skin, and whilst they are easily brushed off by the action of scratching, they also give the characteristic 'biting' sensation
If a static problem has been established, treatment is usually straightforward.
· The affected area should be treated with an anti-static solution on a regular basis.
· Equipment and fixtures should be fitted with earth straps or placed on anti-static mats.
· If possible, carpeting with natural, rather than synthetic fibres should be used.
· Dust and paper fibres etc. should be kept to a minimum.
Good luck……….