Can Deep Vein Thrombosis or any kind of blood clotting come from an insect bite?

A possible spider bite that was untreated might have caused blood cloting in a leg months later.

It's a stretch, but it is possible, at least in theory.
An infected insect bite can cause cellulitus, and cellulitus is associated with a decreased localized blood flow. Compromised blood flow can lead to a DVT. However, a insect bite is a superficially located wound and it would be very unlikely that it would be the cause of a DVT, which is obvously not superficial, but just the opposite---DEEP. But, if the insect bite lead to immobility, then YES, it could be dirrectly related.
See your doctor. If you are suspecting a DVT a simple ultrasound examination can confirm or rule it out.

According to http://www.nlm.nih.gov/medlineplus/ency/... causes, incidence, and risk factors for DVT follows:

Deep venous thrombosis (DVT) affects mainly the veins in the lower leg and the thigh. It involves the formation of a clot (thrombus ) in the larger veins of the area. This clot may interfere with circulation, and it may break off and travel through the blood stream (embolize). A resulting embolus can lodge in the brain, lungs, heart, or other area, causing severe damage to that organ.

Risks include prolonged sitting, bedrest, or immobilization (such as on long plane or car trips), recent surgery or trauma (especially hip, knee or gynecological surgery), fractures, childbirth within the last 6 months and the use of medications such as estrogen and birth control pills.

Risks also include a history of polycythemia vera, malignant (cancerous) tumor, and inherited or acquired hypercoagulability (a condition where the blood is more likely to clot).

Deep venous thrombosis is most common in adults over age 60 but can occur in any age group.

No, not really but consult with your doctor.

No, if you are suffering from DVTs talk to your doctor. Do not be concerned about insect bites.

DVT is caused by lack of circulation in the legs ppl in hospital who had surgery might get it since they are not always taken out of bed to walk or ppl in wheelchairs. my mom died from it cause the after care home she was in was lazy and didnt get her up to walk when they were suppose to. the blood clot goes straight to your heart and bursts then you die

Only time I've even remotely heard of an insect bite causing a DVT is from a brown recluse spider bite. Normally there are many more symptoms before it could/would get to that, and you'd know what the cause would be, and hopefully already in medical care.

I agree that a brown recluse spider bite could cause tissue necrosis resulting in veneous insufficiency, but that is remote.