Ch. 6 — Alternatives to Animal Use in Research • 135 
• Communication. Honeybees recruit others 
to a new food source through a dance per- 
formed at the hive that conveys distance and 
directional information (209). Many species 
of insects (e.g., moths and ants) communicate 
chemically by pheromones, which serve sex 
attractant, repellant, and/or trail-marking 
functions (reviewed in ref. 30). Other species, 
such as the cricket, communicate by songs 
produced by rubbing body parts together (19). 
• Navigation. Honeybees have demonstrated 
extraordinary abilities to locate and return to 
a food source "mapped out” for them by other 
bees . They can also return to an artificial feed- 
ing source designed for experimental pur- 
poses to test their navigation abilities (37, 
209,215). 
• Learning and Memory. Habituation has been 
demonstrated in a variety of insect species (46). 
Honeybees also appear capable of more ad- 
vanced forms of learning, such as learning to 
associate a specific color with a food reward, 
and they can remember this association after 
a 2 -week interval (219). Cockroaches can learn 
to leave their preferred dark retreats and stay 
in the light to avoid being shocked; ants have 
been trained to travel a maze to receive food 
rewards (85). 
• Behavioral Genetics. Because of the relative 
ease with which their chromosomes and in- 
dividual genes can be identified, fruit flies have 
been used extensively to elucidate the genetic 
basis for a variety of behaviors (132). 
Habituation has been demonstrated in a variety 
of spiders (45), and spiders are capable of learn- 
ing and remembering the location of prey in their 
webs (85). They can also be trained to associate 
food dipped in quinine or sugar with different 
tones (46). 
Even though protozoa possess both plant- and 
animal-like characteristics and lack nervous tis- 
sue, some forms of learning have been demon- 
strated in these single-celled organisms. Habitua- 
tion has been demonstrated in paramecia (45). 
Although the results generated much controversy 
(reviewed in ref. 45), one investigator claimed to 
have trained paramecia to enter a specific area 
of their water container in order to receive food 
reinforcement (81). It has also been reported that 
paramecia show spontaneous alternation in a T-maze, 
a phenomenon also observed in rodents (139). 
A recent study of learning ability in paramecia 
has demonstrated classical conditioning of an es- 
cape movement (94). This study also found that 
paramecia develop memory for the training event, 
since significantly fewer trials were needed 24 
hours later to relearn the response. Data such as 
these challenge the widely held assumption that 
learning is a property of synaptic interactions be- 
tween nerve cells— absent in protozoa— and not 
of individual cells themselves. 
Plants 
From a behavioral perspective, plants differ from 
animals in two principal ways. First, plants lack 
the means of achieving rapid intra- and inter- 
organismal communication and coordination due 
to the absence of a nervous system. However, 
plants do regulate intra -organismal activities occur- 
ring at different sites through the use of hormones . 
Plants and animals thus share the basic principles 
of endocrine function. Second, plants differ from 
animals in that they are stationary. They must wait 
for energy to come to them, while most animals 
move about to obtain different sources of energy. 
Despite these differences, plants do show rudi- 
mentary forms of behavior (188). Plants can grow 
and move in response to light, and some plants 
have achieved the capacity for relatively rapid 
movement to exploit certain animals as prey (e.g., 
the venus fly trap). The mimosa plant, which can 
fold its leaves when touched, has been a subject 
of particular interest. Certain of its cells appear 
to generate primitive action potentials— electrical 
activity that may be analogous to neuronal func- 
tioning in animals (186). There have also been 
reports that the folding response of the mimosa 
plant shows habituation (6) and even some of the 
rudiments of classical conditioning (8). Although 
some claim evidence of feelings, emotions, and 
even thinking in plants based on polygraph record- 
ings (206), others contend these are artifactual (80). 
A number of plants defend themselves from 
predators via thorns, stickers, or toxic chemicals 
that produce sickness, irritation, or even death if 
touched or consumed. It has been demonstrated 
