Two neurons communicate with each other through the released at the site to initiate action potential and carry the signal through the body

Two neurons communicate with each other through the synapse.  The neurotransmitter released at the site to initiate action potential and carry the signal through the body  

 Two neurons are in a connection through the synapse which includes the presynaptic neuron and the postsynaptic cell. There can be two types of synapses:
·     Chemical synapse: the presynaptic cell releases neurotransmitter which binds to the receptor on the membrane of the postsynaptic cell.
·     Electrical synapse: the presynaptic and postsynaptic cell membranes are connected by special channels are capable of passing an electric signal

The hawk receives 0.1% energy from the caterpillar although the caterpillar gets eaten by another bird smaller than the hawk first