Yes, i think so.

I have read that many bio Weapons are  impossible to be noticed until they kills millions. Bioweapons can infect thousands and keeps before anyone finds out about the source.

More info:

Biological warfare, as defined by the United Nations, is the use of any living organism (e.g. bacterium, virus) or an infective component (e.g., toxin), to cause disease or death in humans, animals, or plants. In contrast to bioterrorism, biological warfare is defined as the "state sanctioned" use of biological weapons on an opposing military force or civilian population. Biological weapons include pathogenic viruses, bacteria, and biological toxins. Of particular concern are genetically altered microorganisms, which are engineered to target a specific group of people.(http://www.encyclopedia.com/topic/biological_warfare.aspx)

Biological warfare (BW)—also known as germ warfare—is the use of biological toxins or infectious agents such as bacteria, viruses, and fungi with the intent to kill or incapacitate humans, animals or plants as an act of war. Biological weapons (often termed "bio-weapons", "biological threat agents", or "bio-agents") are living organisms or replicating entities (viruses, which are not universally considered "alive") that reproduce or replicate within their host victims.(https://en.m.wikipedia.org/wiki/Biological_warfare)

Yes, i think so.

I have read that many bio Weapons are  impossible to be noticed until they kills millions. Bioweapons can infect thousands and keeps before anyone finds out about the source.

More info:

Biological warfare, as defined by the United Nations, is the use of any living organism (e.g. bacterium, virus) or an infective component (e.g., toxin), to cause disease or death in humans, animals, or plants. In contrast to bioterrorism, biological warfare is defined as the "state sanctioned" use of biological weapons on an opposing military force or civilian population. Biological weapons include pathogenic viruses, bacteria, and biological toxins. Of particular concern are genetically altered microorganisms, which are engineered to target a specific group of people.(http://www.encyclopedia.com/topic/biological_warfare.aspx)

Biological warfare (BW)—also known as germ warfare—is the use of biological toxins or infectious agents such as bacteria, viruses, and fungi with the intent to kill or incapacitate humans, animals or plants as an act of war. Biological weapons (often termed "bio-weapons", "biological threat agents", or "bio-agents") are living organisms or replicating entities (viruses, which are not universally considered "alive") that reproduce or replicate within their host victims.(https://en.m.wikipedia.org/wiki/Biological_warfare)

Very scary! It will be more dangerous. But even conventional weapons end up contaminating water and soil. Remember the Yugoslavia war of '99 with DU weapons?

So many pilots from Italy died from leukaemia by just flying the bombs (before they dropped them), never mind receiving them on the ground.

Because of its effects, biological warfare is the most dangerous.

No doubt about that. By and large, biological weapons are much worse than physical or chemical weapons. The basic reason is that to-date none of us are entirely sure about the behaviour of biological agents when used as weapons. As a matter of fact, the understanding of biological processes is much newer than our knowledge of physical and chemical phenomena.

I have the impression that the protocols for the use of physical weapons is more consolidated than about biological weaponry. 

it is greed, if we could find medicine to cure this disease most of our problems will be solved.

All weapons are bad. Biological war and weapons of massive destruction should never exist. Ideally, the trend of true human development should point for all weapons being at least minimized or even totally banned. Violence only generates more violence.

Biological war targets a whole population/ethnic group based on their genetic characteristics (may not be the only method, but a very destructive one), this would make it incredibly destructive than the traditional weapons. Yes, if there is a possibility that human beings can annihilate themselves, I guess they themselves would be the most probable perpetrators. 

Any war is bad- no happy results- to satisfy human ego and greedness- wars are fought- As long as Oil is on earth- Wars around those countries will remain- When oil will finish- there will be no war in mideast at all.

No difference between normal war and biological war- death occurs in both- Biological war need highly skilled scientists on the background but is cheaper to kill people on the front- but can be very dangerous for the party if those skills are lacking,

Conventional wars are very expensive on the front which needs more military and equipment. Both kind of wars are bad for victims.

Biological warfare is the term given to the use of infectious agents such as bacteria, viruses, fungi or their by-products to wreak death and havoc among a specific population.  As a result, the user achieves control over an area or a segment of the population by weakening the ability to resist.  Biological weapons don’t necessarily have to kill humans: unleashing a horde of locusts to destroy crops or agents that kill livestock can be just as effective.

The perfect biological weapon would have these characteristics:

• Be infectious and contagious in a large percentage of those exposed
• Cause severe long-term debilitation or death of the infected organism
• Have few available antidotes, preventives or cures
• Be easily deliverable to the area or population targeted
• Have low likelihood of causing damage to those using the agent

There are several types of viral fevers associated with different organisms that normally infect rodents.  Hemorrhagic Fevers like Ebola start off with fever, diarrhea,  and weakness, but progress to more serious problems relating to internal and external hemorrhaging. Patients may bleed from eyes, ears, nose, mouth, or rectum and may have bruising on the skin from subcutaneous bleeding. 

http://www.truthistreason.net/biological-warfare-and-its-effects

Yes

Biological weapons are "the poor man's atom bomb,"

http://news.stanford.edu/pr/01/bioterror117.html

Biological warfare agents may be more potent than conventional and chemical weapons. During the past century, the progress made in biotechnology and biochemistry has simplified the development and production of such weapons. In addition, genetic engineering holds perhaps the most dangerous potential. Ease of production and the broad availability of biological agents and technical know how have led to a further spread of biological weapons and an increased desire among developing countries to have them.

Examples of biological and chemical warfare use during the past 2000 years

Time and event:

600 BC --Solon uses the purgative herb hellebore during the siege of Krissa

1155 -- Emperor Barbarossa poisons water wells with human bodies in Tortona, Italy

1346 -- Tartar forces catapult bodies of plague victims over the city walls of Caffa, Crimean Peninsula (now Feodosia, Ukraine)

1495 -- Spanish mix wine with blood of leprosy patients to sell to their French foes in Naples, Italy

1675 -- German and French forces agree to not use “poisones bullets”

1710 -- Russian troops catapult human bodies of plague victims into Swedish cities

1763 -- British distribute blankets from smallpox patients to Native Americans

1797 -- Napoleon floods the plains around Mantua, Italy, to enhance the spread of malaria

1863 -- Confederates sell clothing from yellow fever and smallpox patients to Union troops during the US Civil War

World War I -- German and French agents use glanders and anthrax

World War II -- Japan uses plague, anthrax, and other diseases; several other countries experiment with and develop biological weapons programs

1980–1988 -- Iraq uses mustard gas, sarin, and tabun against Iran and ethnic groups inside Iraq during the Persian Gulf War

1995 -- Aum Shinrikyo uses sarin gas in the Tokyo subway system

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1200679/

Yes of course.

Biological warfare used in the past  and  recent. As Kausel posted her answer its one of lethal  machine. May be all the following diseases or viruses are trials of biological weapons: BSE, H5N1, H1N2, H3N2 and  H3N2, and H2N3.

yes

Any plan in action to kill people is dangerous. It is difficult to accept that human being have so far and yet he is unable to respect others around him.

Yes. Because the enemy is invisible in biological war.

The Basics of Chemical and Biological Weapons

Like a nuclear bomb, a chemical or biological weapon is a weapon of mass destruction. An effective attack using a chemical or biological agent can easily kill thousands of people.

A biological weapon uses a bacteria or virus, or in some cases toxins that come directly from bacteria, to kill people. If you were to dump a load of manure or human waste into a town's well, that would be a simple form of biological warfare -- human and animal manure contain bacteria that are deadly in a variety of ways. In the 19th century, American Indians were infected with smallpox through donated blankets.

A modern biological weapon would use a strain of bacteria or a virus that would kill thousands of people. Tom Clancy has explored the idea of biological terrorism in two books: "Executive Orders" and "Rainbow Six." In both books, the source of infection is the Ebola virus. In these plot lines, the infection is spread through small aerosol cans (like those used by insecticide products to create "bug bombs") released at conventions, or through misting systems used to cool sports venues.

http://science.howstuffworks.com/biochem-war2.htm

Yes, I think so.

Yes , that's right ..

Yes, that's right

World has experienced the destruction of weapons, like Atomic Bomb, but not a biological war. In my opinion physical weapons developed so far are more destructive than the biological weapons

Historically, outbreaks (wars) of microbial species against the human species have killed far more people than war itself. Examples include i) killing of 95% of Pre-Columbian Native American populations by diseases like small pox, measles, plague, typhoid and influenza; ii) death of 25 million Europeans (a quarter of the population) caused by Bubonic Plague in the 14th century and 21 million deaths due to the influenza pandemic of 1918-1919 (1).Worldwide, naturally occurring infectious diseases remain the major causes of death. In the United States, the impact of a number of very virulent biological agents and/or their toxins has been drastically reduced because of a very accessible health care system and excellent public health infrastructure. Still, a substantial number of people (approximately 70,000) die each year from infectious diseases (2). The travel and trade necessary for economic globalization, continued potential for transmission of infectious agents from animals to humans, and large populations living in proximity in major urban areas of the world, make disease outbreaks a major threat. The resistance of common pathogens to the available antimicrobial agents adds significantly to the threat. Advances in public health, diagnostic and pharmacological interventions are needed to protect the population from emerging and re-emerging infectious diseases. The global nature of infectious disease threats is well described in a statement prepared by Dr. David L. Heymann, Executive Director for Communicable Diseases, World Health Organization. This statement was presented to the Committee on Foreign Relations, United States Senate, during a hearing on "The Threat of Bioterrorism and the Spread of Infectious Diseases" on September 5, 2001 (3).

----http://www.siumed.edu/medicine/id/bioterrorism.htm

War is always dangerous, but, as microbiologist I think bacterial or viral weapons can be far more destructive and could spread and escape controls measure in an easyer way than mechanical stuff... Humankind can be destroied with a single bacterial cell, if used umproperly.

Maybe not in general, but you have not control of the actual proliferation of a biological weapon. If highly damaging to health, then the result would be beyond kinetic interchanges.

Please, read the following quote:

Hi:

Both Biological and physical weapons are weapons of mass destruction. However, Biological weapons are self-replicating, so, it can continue spreading up to size of global pandemic of the whole world. Also, it don’t distinguish between foes and friends and pandemic can kill also own people.

 Regards