Flea bites can linger on bedding and other fabrics for days, depending on the severity of the infestation. Although fleas typically have a lifespan of only a few days, their bites may remain visible for at least that long. To help reduce flea bites, it's important to take preventative measures such as washing your bedding in hot water with insecticidal detergent and regularly vacuuming any eggs or larvae from carpets and furniture. In extreme cases where flea bites become frequent, consulting a medical professional for advice and treatment is also advisable.

To further prevent infestations, using flea repellents, like sprays or powders, can help keep them away from bedding. Additionally, treating pets with an approved medication will generally stop them from carrying any fleas into the home. Taking other precautionary steps such as reducing sources of infestations in areas like carpets or furniture can also aid in avoiding flea bites on sheets.

When a severe infestation has occurred and blood spots are visible on fabrics, replacing them may be necessary as the fleas may have already laid eggs which could further perpetuate the cycle if not removed completely.

Ultimately when dealing with an issue such as this one it's best to exhaust all relevant options before going so far as to replace bedding or mattresses altogether; though this may provide some relief from severe cases by essentially "clearing out" affected materials; consulting medical professionals first to understand treatments and medications before taking this measure should be considered if possible.

Flea bites can transfer blood onto fabrics, like sheets and other materials, creating a permanent stain. To prevent this, it's important to take proactive steps: regularly inspect pets for fleas and treat them with the appropriate medication; vacuum the area frequently and treat carpets or pet beds with flea treatments; and in cases of extreme infestations, replace bedding or other fabrics.

If stains already exist due to flea bites, hot water and laundry detergent may help remove them. However, if that doesn't work, you'll need to replace the fabric or mattress. When selecting a new mattress, make sure it's dust mite resistant and has anti-allergen properties; natural materials will provide ventilation and breathability so your sleep environment remains free of allergens such as dust mites. Additionally, wash linens in hot water regularly to kill off any remaining dust mites or allergens while also giving your sheets a deep cleanse.

Taking preventive measures-inspecting pets for signs of infestation & treating promptly-along with investing in an allergen-resistant mattress can reduce the risk of fleas causing stains significantly. If all else fails however, replacing affected fabric or mattresses may be necessary in order to remove any unsightly fleabite-related stains permanently.