Ants are not specifically drawn to blood the way they are to sugar or grease, but they will feed on it when they encounter it. Blood contains proteins, salts, and small amounts of glucose, all of which provide nutritional value to ants. So while a drop of blood on your kitchen counter won’t attract a trail of ants the way a spill of honey would, ants that come across blood will readily consume it.
What in Blood Attracts Ants
Ants are opportunistic omnivores. Different species prioritize different nutrients depending on what their colony needs at any given time, but most ants seek out three things: sugars for quick energy, proteins for larval growth, and fats. Blood offers two of those. It is rich in protein (mainly from hemoglobin and albumin) and contains dissolved salts like sodium and potassium that ants actively seek out, especially in environments where salt is scarce.
The sugar content of blood is relatively low compared to fruit juice or nectar, which is why blood doesn’t trigger the same intense foraging response that sweet substances do. But for protein-seeking species, or colonies in a growth phase producing lots of larvae, blood is a useful food source. Dried blood is less attractive than fresh blood because it becomes harder for ants to consume, though some species will still work at it.
Why Ants Show Up Around Wounds
People often notice ants on scrapes, cuts, or used bandages, which can be alarming. Several things explain this. An open wound leaks small amounts of blood, serum, and other fluids that contain proteins and sugars. The warmth and moisture of a wound also make it easier for ants to detect using their chemical sensors. Fire ants in particular are known for being attracted to wounded or immobile animals, and their bites can make the situation significantly worse.
In forensic science, ants are documented feeding on human tissue after death, particularly along wound edges and areas where blood has pooled. They typically feed on the outermost skin layer rather than burrowing deep into tissue. This feeding can create small, patterned marks that investigators sometimes need to distinguish from injuries that occurred before death.
Which Ant Species Are Most Likely to Feed on Blood
Not all ants respond to blood equally. Species that lean heavily toward protein in their diet are more interested than sugar-loving species.
- Fire ants are among the most likely to be attracted to blood and wounds. They are aggressive foragers that target animal protein and are known to swarm injured animals or people who cannot move away.
- Argentine ants are generalist feeders that will consume blood along with almost anything else organic they encounter.
- Carpenter ants primarily seek sugary liquids like honeydew, so blood is less appealing to them unless other food is unavailable.
- Pharaoh ants are a particular concern in hospitals because they actively seek out protein-rich substances, including blood on wound dressings and surgical sites. They are small enough to enter bandages and sterile packaging.
Blood vs. Other Substances Ants Prefer
If you ranked common household substances by how strongly they attract ants, blood would fall somewhere in the middle. Sugar water, honey, fruit juice, and grease all generate stronger and faster foraging responses. Blood is roughly comparable to meat scraps or pet food in its attractiveness. It provides solid nutrition but doesn’t send ants into the same frenzy as concentrated sugar sources.
One factor that changes this is salt content. In tropical and inland environments where sodium is hard to find, ants will go out of their way to collect salty fluids. Blood, with a sodium concentration of about 0.9%, becomes more attractive in these settings than it would be in a coastal area where salt is abundant. Researchers studying tropical ant communities have found that salt can be as powerful an attractant as sugar for certain species in sodium-poor habitats.
Keeping Ants Away From Blood and Wounds
If you’re dealing with ants around bandages, pet injuries, or even a spot of blood on the floor, a few practical steps help. Clean up any blood spills promptly with soap and water, since even a thin residue can attract scouts. For wounds on pets that spend time outdoors, covered bandages are essential, particularly in areas with fire ants. Used bandages and gauze should go into sealed trash bags rather than open bins.
For bedridden individuals or animals, keeping the immediate area free of food debris reduces the chance that scout ants will discover wounds while foraging nearby. Pharaoh ants in medical facilities are a recognized hygiene concern, and hospitals in warm climates use targeted pest control specifically to keep them away from patient care areas.